Question

the ages of a and b are in the ratio 7:2 . after 8 years the ratio of their ages will be 5:2 find their present ages

Answer 1

Answer:

LET A BE ASHA

AND LET B BE SUSHMA

Ratio of the ages of Asha and Sushma= 7:2.

Let the common multiple be x

Therefore the present age of Asha= 7x and

The present age of Sushma= 2x.

Eight years hence,

The ratio of their ages= 5:2.

7x+8/2x+8= 5/2

2(7x+8)= 5(2x+8) [Cross multiplication]

14x+16= 10x+40

14x-10x= 40-16

4x= 24

x= 24/4= 6.

Present age of Asha= 7(6)= 42 years old.

Present age of Sushma= 2(6)= 12 years old.

Answer 2

Answer:

let a ages=7x

b age=2x

after 8years a age=7x+8

after 8years b age=2x+8

according to questions=

7x+8/2x+8=5/2

cross multiply we get

2into 7x+8=5into2x+8

14x+16=10x+40

14x-10x=40-16

4x=24

x=24/4=6

x=6

a =7x=7*6=42 years

b=2x=2*6=12