Question

The ages of A and B are in the ratio of 5:7. Four years from now the ratio of their ages
will be 3:4. The present age of B is
(a) 20 Years fb 28 Years (c) 15 Years (d) 21 Years​

Answer 1

Answer:

Step-by-step explanation:

let present age of hari be 5x

then present age of harry be 7x

According to question

5x+47x+4=34

4(5x+4)=3(7x+4)

20x+16=21x+12

x=4

present age of hari=5x=5*4=20 years

present age of harry=7x=7*4=28 years.

Answer 2

Let present age of A and B be 5x and 7x respectively.
Their ages after 4 years 5x+4 and 7x+4
it is given that the ratio of ages after 4 years is 3:4
Acc.to eq.
5x+4/7x+4=3/4
4(5x+4)=3(7x+4)
20x+16=21x+12
16-12=21x-20x
4=x
Present age of B= 7×4=28 years