Question

the ages of a and b are in ratio 5:7 eight years ago their ages were in ratio 7:13 find their present age

Answer 1

Hope this help you!!

Answer 2

Given:

Ratio of ages of a and b=7:5

ratio of their ages 8 years ago=7:13

To Find:

Present age of a and b.

Solution:

Let the present ages of a and b be 5x and 7x years respectively.

a's age 8 years ago=(5x-8)years

b's age 8 years ago=(7x-8)years

∴$\dfrac{5x-8}{7x-8}=\dfrac{7}{13}$

⇒$13(5x-8)=7(7x-8)$

⇒$65x-104=49x-56\\65x-49x=104-56\\16x=48\\x=\dfrac{48}{16}=3$

a's present age=$5\times3=15 years$

b's present age=$7\times3=21years$

∴a's andb's present age is 15years and 21years respectively.