Let 'N' is the smallest number which divided by 13 and 16 leaves respective remainders of 2 and 5.Required number = (LCM of 13 and 16) - (common difference of divisors and remainders) = (208) - (11) = 197.
Let the father's age be x and son's age yTherefore, x + y = 60 ....................(i)Five years back, (x - 5) = 4 (y - 5)x - 4y = - 15 ......................(2)Solving (1) and (2), x = 45 and y = 15