Question

Sum of the ages of two brothers at present is 77 times the difference in their ages. After 55 years, the sum of their ages will be 99 times the difference in their ages. The present age of younger brother is:

Answer 1

x + y = 100        (1)
x - 30 = 3(y - 30)    (2)

(2): x - 30 = 3y - 90
x = 3y - 60.

(1): (3y - 60) + y = 100
4y = 160
y = 40.

Answer 2

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