Question

The ratio between present age of a and b is 6:7. If b is 4years older than a, what will be the ratio of the ages of a and b after 4 years.

Answer 1

ratio of age of a to b = 6/7
let a's age be 6x years and b's age be 7y years.

we know b is 4 years older than a therefore b's age with respect to a = (6x+4) years.

therefore the ratio of their present age => 6/7 = 6x/(6x+4)
=> 36x +24 = 42
=> 36x = 42- 24
=> 36x = 18
=> x = 18/36
=> x = 1/2

therefore present age of a= 6x
a= 6×1/2
a= 3 years
hence, present age of b=6x+4
b=3+4
b=7 years.

Now, after 4 years,
age of a = 7 years
age of b = 11 years.
therefore the ratio is = 7:11