calves of domestic cows and hawaiian monk seal pups both again mass at a constant rate for at least two months from birth. An average calf will weigh 75 pounds on the second day after its birth, and 120 pounds on day 20. An average seal pup will weigh 124 pounds on day 24 and 196 pounds at weaning, day 42. At what age would a calf and a seal pup weigh the same?