132 = 11 * 3 * 4Clearly, 968 is not divisible by 3None of 462 and 2178 is divisible by 4And, 5284 is not divisible by 11Each one of the remaining four numbers is divisible by each one of 4, 3 and 11.So, there are 4 such numbers.
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
EXAMIANS