Question

The present age of rohit and sunil are in the ratio of 3:5. 10 years hence , the ratio of their ages will be 4:5. find the present age of rohit.

Answer 1

Answer:

The present age of rohit is 6 years

Step-by-step explanation:

Let the present ages or rohit and sunil be x and y respectively.

As per given data,

x:y = 3:5

Then, x = 3k, y=5k

After 10 years

x+10 : y+10 = 4 : 5

$\implies\:\frac{x+10}{y+10}=\frac{4}{5}$

$\implies\:\frac{3k+10}{5k+10}=\frac{4}{5}$

$\implies\:5(3k+10)=4(5k+10)$

$\implies\:15k+50=20k+40$

$\implies\:50-40=20k-15k$

$\implies\:10=5k$

$\implies\:k=2$

$\therefore\:$The present age of rohit is 3(2) = 6 years

Answer 2

Answer:-

Step-by-step explanation:

Given:-

Present age of Rohit and Sunil are in ratio 3:5.

Then,

Let the present age of Rohit and Sunil be 3x and 5x.

After 10 years

Age of Rohit = 3x + 10  

Age of Sunil = 5x + 10  

Solution:-

⇒ (3x + 10)/(5x + 10) = 4/5  

⇒ 5(3x + 10) = 4(5x + 10)  

⇒ 15x + 50 = 20x + 40  

⇒ 5x = 10  

⇒ x = 10/5

⇒ x = 2.

Age of Rohit = 3x = 6  years.

Age of Sunil = 5x = 10 years.