delivered the opinion of the Court.
Plaintiff sued the Great Falls YMCA for negligence after his son, Mark, was found submerged in defendant’s swimming pool. A jury returned a verdict for defendant, and plaintiff appeals. We affirm.
At the outset, we note that appellant’s brief does not contain a separate statement of issues presented for review, as required by Rule 23(a)(2), M.R.App.Civ.P., which makes our ferreting out appellant’s arguments a more difficult and time-consuming task. Counsel are admonished to conform their briefs to Rules 23 through 27, M.R.App.Civ.P.
In May 1977 Mark brought home from his school one of defendant’s brochures. In this brochure was a description of the “Summer Action Club” which was advertised “safe, well-supervised and inexpensive.” Upon payment of the required fee, Mark, age six, was enrolled in the Club and his particular class was to run from June 27, 1977, to July 1, 1977. A day’s activities in the Club usually concluded with a “free swim” period in defendant’s indoor pool, where there was no formal instruction but individual informal instruction was occasionally given. The shallow and deep parts of the pool were divided by a rope.
Pam Boyle, a certified senior lifeguard at the YMCA, gave Mark instructions on how to swim so that he was able to dog-paddle the width of the pool without assistance. On June 30, 1977, the Summer Action Club members had the usual “free swim” period at the end of the day. There were *39not more than twenty-five people in the pool at this time and attendant at the pool were five counselors, including Boyle and another senior lifeguard. All five were qualified in lifesaving.
The facts surrounding Mark’s submersion in the water are in dispute. Missy Blais, one of the junior counselors, stated by affidavit that she noticed Mark playing with two other boys and hanging onto the edge of the pool about two feet from the dividing rope, on the deep end side. A short time later she was summoned by one of the two boys who told her that they had been playing with Mark but he had not come up yet. However, there was other testimony indicating that Mark had been running and had fallen in. At any rate, Blais found Mark submerged in about four and one-half feet of water, six to eight inches from the bottom of the pool and drifting towards the middle of the pool.
Blais and a boy pulled Mark from under the water and yelled for help. What happened next is also in dispute. Blais claimed she carried Mark to the edge of the pool and that Mark was given no mouth-to-mouth resuscitation while in the water. Boyle, on the other hand, testified that she met Blais in the water carrying Mark, grabbed Mark by the hair and swam to the side of the pool. Boyle further testified that, while still in the water, she gave Mark two quick breaths of air, using artificial resuscitation, and Mark vomited. After clearing his mouth out, she gave him two more quick breaths, and he vomited again. Mark was then lifted out of the water where cardio-pulminary resuscitation was administered until ambulance personnel arrived. One of the ambulance personnel (Cherewatenko) testified that when he arrived Mark was unconscious but was breathing and had a weak pulse. Mark was then taken to the hospital where he stayed for four days, two of which were for observation purposes.
On April 14, 1978, plaintiff filed a complaint alleging that defendant was negligent in the care and supervision of Mark. Defendant answered, denying the negligence allega*40tions and generally contending that defendant had exercised ordinary care in supervising and assisting Mark when he became endangered.
The parties exchanged numerous interrogatories and submitted pretrial memoranda. Plaintiff’s motion for summary judgment on the issue of liability was denied. At trial, one of the major issues was the length of time Mark was under water. The trial judge admitted, over plaintiff’s objection, Boyle’s testimony regarding an experiment performed by her thirty minutes after the incident. In this experiment, she threw a diving ring into the pool at the location where Mark was recovered and timed how long it took two young boys (one of whom had helped pull Mark from under the water) to retrieve it. Boyle concluded from this experiment that Mark was under water for about thirty seconds or at the maximum, one to one and one-half minutes. A ten-pound diving weight was also thrown in so that it settled near the drain in the pool, and the boys were unable to retrieve it. From this, Boyle concluded that Mark was not on the bottom of the pool when rescued.
During the trial, plaintiff called psychologists to testify that Mark had a learning disability proximately caused by the lack of oxygen during his submersion in the water. Defendant called the treating physician who testified that no brain damage had occurred. After receiving the judge’s instructions, which included statements addressing the proper standard of care, the jury returned a verdict for the defendant. Plaintiff’s motion for a new trial was denied, and plaintiff appeals.
The following issues are raised on appeal:
1. Whether the District Court erroneously admitted the testimony regarding the diving ring experiment;
2. Whether plaintiff is entitled to a new trial because of newly discovered evidence or because of defendant’s abuse of pretrial discovery;
3. Whether the District Court erroneously instructed the jury on the proper standard of care; and
*414. Whether the District Court erred in failing to grant plaintiffs motion for summary judgment on the issue of liability.
Initially, appellant argues that Boyle’s testimony regarding the diving ring experiment was improperly admitted because the test was not conducted under “substantially similar” conditions. Appellant further argues that Boyle was not qualified as an expert to compare the differences between how a human body would react in water as opposed to the diving ring.
Respondent counters that a sufficient foundation was laid and relies on Hurly v. Star Transfer Company (1962), 141 Mont. 176, 376 P.2d 504. In Hurly, we stated that the trial court has discretion on whether to admit evidence of an experiment and substantial similarity of conditions between the experiment and the actual incident is all that is necessary.
The testimony regarding the diving ring experiment was properly admitted. This evidence supported the conclusion that it took one to one and one-half minutes to retrieve the victim from the pool. Thus, no brain damage could have occurred in view of one doctor’s expert testimony that for brain damage to occur the victim must be deprived of oxygen for three to four minutes. Moreover, another doctor testified that lack of oxygen for five minutes is required before brain damage occurs.
Also, the circumstances of the experiment here were substantially similar so as to allow the admission of Boyle’s testimony. The experiment was conducted thirty minutes after the incident and involved the same boy who had helped pull Mark out of the water. Although it is obvious that a diving ring or diving weight has different dimensions than a small body, this evidence was probative to provide the fact finder with an indication of the time involved in effecting the rescue. The trial judge did not abuse his discretion in allowing evidence of the experiment. Hurly, supra. See also, Hanson v. Howard O. Miller, Inc. (1969), 93 Idaho 314, 460 *42P.2d 739 (admission of a braking experiment of a different kind of car than that involved in the accident was left to the sound discretion of the trial court).
Appellant next argues that he is entitled to a new trial because of newly discovered evidence and defendant’s pretrial discovery abuses. Regarding the pretrial discovery abuse, appellant argues that defendant was allowed to add four new witnesses the day before the trial, including Boyle. According to appellant, defense counsel knew of Boyle’s whereabouts (from an undated letter received by defendant describing the incident) but failed to inform plaintiff of her address in violation of defendant’s duty to supplement its interrogatory answers.
Respondent admits that it did not provide Boyle’s Nebraska address to plaintiff but contends that it would have heen a useless act because the address was outdated and would not have led to contact with Boyle anyway. Respondent argues that it had received a phone call that Boyle had come to Great Falls on her own during her 1980 Christmas vacation (the trial started January 7,1981) and this was the first time that defendant knew of Boyle’s whereabouts. Respondent also claims that appellant abused the discovery process because ambulance employee Cherewatenko was never identified in interrogatory answers as being an expert, was never identified in appellant’s pretrial memorandum as being a witness, and Cherewatenko would not discuss the case with defense counsel. Cherewatenko later testified as an expert in the case.
Neither counsel’s action in this regard is commendable as both were lax in keeping the other party informed of pretrial developments and in supplementing answers to interrogatories. The District Court did not commit reversible error by allowing Boyle to testify. Appellant strenuously objected to her testimony because she was going to testify that Mark could swim whereas appellant had previously been under the impression that he could not. However, Boyle was intimately involved in the incident. Her testi*43mony was probative of the matter surrounding the resuscitation of Mark and the amount of time that he was deprived of oxygen.
Moreover, plaintiff interviewed Boyle prior to trial and rejected offers of a continuance by defendant and the trial judge. Under the circumstances here, plaintiff should have requested a continuance, Kipp v. Wong (1974), 163 Mont. 476, 517 P.2d 897, and Hill v. McKay (1908), 36 Mont. 440, 93 P. 345. Plaintiff argued against such continuance, submitted his case to the jury and, after an adverse jury verdict, seeks a new trial. Plaintiff is not entitled to have his cake and eat it too.
Appellant also argues for a new trial on the ground of newly discovered evidence, i.e., Missy Blais was located in Portland, Oregon, after the trial and an affidavit obtained from her differed in several aspects from Boyle’s testimony. Although a counteraffidavit of Blais (submitted by defense counsel to correct some of the statements in Blais’s original affidavit) was filed, it still appears that Blais did not remember handing Mark to Boyle or Boyle giving Mark mouth-to-mouth resuscitation in the pool.
The statute describing grounds for a new trial states in pertinent part:
“Grounds for new trial. The former verdict or other decision may be vacated and a new trial granted on the application of the party aggrieved for any of the following causes materially affecting the substantial rights of such party: a
“(4) newly discovered evidence material for the party making the application which he could not, with reasonable diligence, have discovered and produced at the trial;. . .” Section 25-11-102, MCA.
The statute requires that newly discovered evidence could not have been discovered with reasonable diligence. In his brief, plaintiff does not deny that one of plaintiff’s witnesses, Lisa Galligos (who was called at trial by plaintiff and was listed as one of the plaintiff’s witnesses on both *44pretrial orders) knew where Blais was all along. A simple inquiry by plaintiff of one of its own witnesses would have been sufficient. Further, in one of defendant’s answers to plaintiff’s interrogatories, Blais was described as having pulled Mark from under the water and having taken him to the edge of the pool. This established Blais as a crucial witness. Had plaintiff interrogated his witnesses more thoroughly prior to trial and during preparation of his case, he would have discovered the whereabouts of Blais.
Appellant next argues that the District Court erroneously instructed the jury on the proper standard of care by refusing to give three proposed instructions, which specifically stated that a greater degree of care is owed to a child than to an adult. The court sustained objections to these instructions on the grounds that they did not state the law in Montana as reflected in Henroid v. Gregson Hot Springs (1916), 52 Mont. 447, 158 P. 824. The court instead gave appellant’s Instruction No. 22, which read:
“When a person undertakes the control of supervision of a child he has the duty to use reasonable care to protect the child from injury. Although such person is not an insurer of the safety of the child, he is required to use reasonable care commensurate with the reasonable foreseeable risk of harm to which the child might be subjected while under his control and supervision.”
Henroid appears to be the sole Montana case discussing a swimming pool operator’s standard of care owed to a child. In Henroid a thirteen-year-old boy who apparently could swim (although plaintiff alleged otherwise) drowned in defendant’s pool. In affirming the trial court’s granting of a nonsuit, this Court said:
“Plaintiff must have had some purpose, however, in alleging that Leo Henroid could not swim and in attempting to prove the fact, and that this fact was known to defendant. It must have been the purpose of this allegation to fix the measure of defendant’s duty in this particular instance. That duty is to be measured by the standard of ordinary *45care (Phillips v. Butte, etc., Fair Ass’n, 46 Mont. 338, 127 Pac. 1011, 42 L.R.A. [N.S] 1076), and ordinary care is care proportionate to the risk to be apprehended and guarded against (Bourke v. Butte, E. & P. Co., 33 Mont. 267, 83 Pac. 470). . .
“Other things being equal, the defendant would owe a higher degree of care to the boy whom it knew could not swim, and who was permitted in the pool, than to one whom it knew could swim. In other words, the ability to swim or the lack of it would be an important factor in the sum of all the circumstances which determine what is and what is not ordinary care.” (Emphasis added.) 52 Mont. at 455-456, 158 P. at 825.
This statement in Henroid appears to be in keeping with other pronouncements on the subject. In Gault v. Tablada (S.D. Miss. 1975), 400 F.Supp. 136, aff'd, 526 F.2d 1405, a six-and-one-half-year-old boy (approximately the same age as Mark here), who could dog paddle a little but could not swim, drowned in defendant’s motel pool. In discussing the standard of care owed to the boy in Mississippi, the court stated:
“In Mock v. Natchez Garden Club, 230 Miss. 377, 92 So.2d 562 (1957), 8 A.L.R.2d 1315, the Mississippi Supreme Court held that the owner or operator of a bathing resort and swimming pool owed a duty to use ordinary or reasonable care for the safety of patrons or to guard against injury to them, and must exercise reasonable care and diligence to provide a reasonably safe place or accommodations and maintain the premises in a reasonably safe condition for their use. This duty varies according to the risk involved and the age of the invitees on the premises, and the defendants were bound to consider whether the pool area, although perhaps safe enough for adult guests, presented any reasonably avoidable dangers to children of tender age. Mock v. Natchez Garden Club, supra at 564. See also, City of Jacksonville v. Stokes, 74 So.2d 278 (Fla.1954). Thus, the known presence of [decedent], as well as various *46other children who were guests at the defendant’s motel, imposed a duty of care upon the defendants commensurate with the facts and circumstances then existing. Waugh v. Duke Corporation, 248 F. Supp. 626 (M.D.N.C.1966). . .” (Emphasis added.) 400 F. Supp. at 139.
The court also noted that in Mississippi, as in Montana, a child under seven cannot be contributorily negligent, 400 F.Supp. at 140. See, Burns v. Eminger (1927), 81 Mont. 79, 261 P. 613, and Graham v. Rolandson (1967), 150 Mont. 270, 435 P.2d 263.
In Bailey v. YMCA (1965), 112 Ga.App. 684, 146 S.E.2d 324, a nine-year-old boy who could not swim drowned in defendant’s swimming pool, and there, as here, no one saw the boy go under the water or knew exactly how he had entered the water. In affirming the jury verdict for defendant and denying plaintiffs motion for a new trial, the court said:
“. . . children of tender age. . .may be entitled to a greater degree of care from adults toward them, proportioned to their ability to foresee and avoid perils which may be encountered; but regardless of the age or capacity of the injured person, if there is no breach of legal duty on the part of the defendant toward that person, there can be no legal liability. Augusta Amusements, Inc. v. Powell, 93 Ga.App. 752, 754, 92 S.Ed.2d 720.” (Emphasis added.) 146 S.E.2d at 337.
The jury was properly charged in the instant case by appellant’s Instruction No. 22. Although it does not specifically state that a greater duty is owed, it expresses the idea that the reasonable care to be accorded the plaintiff by defendant must be commensurate to the foreseeable risk of harm, i.e., the child’s age and maturity are factors to be taken into account in determining what risks are reasonably foreseeable. Henroid, Gault and Bailey, supra, all bear this out.
Moreover, plaintiffs counsel fully argued to the jury the *47proper standard of care and pointed out the particulars of the alleged negligence of Boyle and the defendant. Plaintiffs substantial rights were not prejudiced by the failure to give the requested instructions. Associated Agency for Bozeman, Inc. v. Pasha (1981), Mont., 625 P.2d 38, 38 St.Rep. 344.
Lastly, appellant argues that the District Court erred in failing to grant plaintiffs motion for summary judgment on the liability issue, relying principally on the cases cited as authority in his rejected jury instructions. We do not agree. There were a number of genuine issues of material fact presented by defendant, thereby precluding plaintiffs motion for summary judgment on the issue of liability. Rule 56(c), M.R.Civ.P. For example, there was a factual question of whether defendant had provided a sufficient ratio of lifeguards to pool users according to water safety procedure. There was also a factual question, raised by the complaint and an expert’s affidavit, as to how long Mark was under water which, of course, is the nub of plaintiffs case. Furthermore, there was a factual question of whether defendant had properly instructed its patrons in pool use in accordance with accepted water safety standards. By virtue of these and other factual questions, we hold that the District Court did not err in failing to grant plaintiffs motion for summary judgment on the liability issue.
Affirmed.
MR. JUSTICES DALY, HARRISON, SHEA and WEBER concur.