Question

the age of the father 3 years ago was 2.5 times of his son's age and after 7 years it will be twice the age of his son , the present age of the father and son is ..?

Answer 1

Let the present age of father is A, and the present age of son is B.Then
(A-3) = 2.5(B-3)
A -3 = 2.5B - 7.5
2.5B - A = 4.5 , eq(1)
2(B+7) = (A+7)
2B+14 = A + 7
2B - A = -7 , eq(2)
eq(1) - eq(2) , we get :
0.5B = 11.5
B = 23 yrs
A - 2 × 23 = 7
A = 7 + 46
= 53 yrs