The ratio of ages of Dhruv and Hiral is 3:4. After five years the ratio of their ages will be 4:5.

Report

Report an issue

Name

Email

Message

Submit

Cancel

KPTCL Assistant Exam (Mescom) SLOT1 2017 click here to view all questions

The ratio of ages of Dhruv and Hiral is 3:4. After five years the ratio of their ages will be 4:5. What will be Dhruv's and Hiral's ages after five years?

A20, 25

B15, 20

C30, 40

D16, 20

dhruv ? Jan 6 '2020 at 10:13

Correct answer is: 20, 25

Explanation:

Let the present age of Dhruv and Hiral be D and H. Therefore,

\(\frac{D}{H} = \frac{3}{4}\)

4D = 3H ….(1)

and after 5 years

\(\frac{(D+5)}{(H+5)} = \frac{4}{5}\)

5D + 25 = 4H + 20

4D + D + 5 = 4H 

3H + D + 5 = 4H [From (1)]

D = H-5 ..(2)

From (1) and (2)

4D  = 3H
4(H-5) = 3H
4H-20 = 3H
H = 20

D = H-5
D = 20-5
D = 15

Dhruv age after 5 year = D+5 = 15+5 = 20

Hiral's age after 5 year = H+5 = 20+5 = 25 

All DiscussionsClick here to write answer

Correct answer is: 20, 25 Explanation: Let the present age of Dhruv and Hiral be D and H. Therefore, \(\frac{D}{H} = \frac{3}{4}\) 4D = 3H ….(1) and after 5 years \(\frac{(D+5)}{(H+5)} = \frac{4}{5}\) 5D + 25 = 4H + 20 4D + D + 5 = 4H  3H + D + 5 = 4H [From (1)] D = H-5 ..(2) From (1) and (2) 4D  = 3H 4(H-5) = 3H 4H-20 = 3H H = 20 D = H-5 D = 20-5 D = 15 Dhruv age after 5 year = D+5 = 15+5 = 20 Hiral's age after 5 year = H+5 = 20+5 = 25  dhruv ? answered Jan 6 '2020 at 10:13 All Comments

Post your answers here:

Post

Post your comments here:

Message

Post

Cancel