Question

'X' years ago, Rakesh's age was twice his brother's age and '4X' years ago, Rakesh's age was thrice his brother's age. If it is
known that 'X' is a natural number, then what can be the absolute difference between their present ages?
43
25
20
30
Mark for Review & Next​

Answer 1

The difference between their present ages is 26 years.

Explanation:

• Let their ages are m and n.
• Now m - x = 2 (n -x)
• m - x = 2n - 2x = m + x = 2n
• x = 2n - m -----(1)
• Age 4 years ago.

m - 4x = 3 (n - 4x)

m - 4x = 3n - 12x

m - 3n = 12 x - 4x

m - 3n = - 8 (2n - m)

m - 3n = -16 n + 8 m

16 n - 3n = 8 m - m

13 n = 7 m

Now m - n will be equal to

m - n = m - 7/13 m

m - n = 6m / 13

Here m can be 13, 26, 39