Let Radha's present age = x years.∴ x = 2 (x = 12) - 3= x = 2x - 24 - 3= x = 27∴ Raja's present age = 4/9 x 27= 12 years ∴ Raja's age after 5 years = 12 + 5 = 17 years
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.
Total balls = 4 + 6 + 7 = 17∴ n(S) = 17C1 = 680Two red balls can be selected from four red balls in 4C2 = 6 ways.and the third ball can be selected from the remaining 13 balls in 13C1 = 13 ways.∴ P (E) = 13x6/680 = 39/340