Question

Ratio of present ages of two brothers is 1:2 and 5 yrs back ghe ratio was1:3 .What will be ratio of their ages after 5 years

Answer 1

The ratio of the present ages of two brother is 1:2

and 5 years back the ratio was 1:3.

What will be the ratio of their ages after 5 years?

:

Two brothers ages a & b, now

:

"The ratio of the present ages of two brother is 1:2

a/b=1/2

Cross multiply

2a = b

:

"5 years back the ratio was 1:3

a-5/b-5=1/3

Cross multiply

3(a-5) = b - 5

3a - 15 = b - 5

3a = b - 5 + 15

3a = b + 10

Replace b with 2a

3a = 2a + 10

3a - 2a = 10

a = 10 yrs a's present age

then

2(20) = 20 yrs b's present age

:

"What will be the ratio of their ages after 5 years?" ;10+5/20+5=15/5= 3:5