The ratio of present ages of two brothers is 1 : 2 and 5 years back, the ratio was 1 : 3. What will be the ratio of their ages after 5 years ?

\par Let the present ages of the two brothers be x years and 2x years respectively.

\frac{x - 5}{2x - 5} = \frac{1}{3}

3(x - 5) = (2x - 5)

x = 10

\par Required ratio = (x + 5) : (2x + 5) = 15 : 25 = 3 : 5