Question

The ratio of ages of Kunal and Deepesh is 3:5. After 10 years this ratio becomes 5:7.
What is the present age of Deepesh ?
(A) 20 years
(B) 25 years
(C) 50 years
(D) 15 years​

Answer 1

Solution :

Let Kunal's age be 3x and Deepesh's age be 5x

After 10 years :

• Kunal's age = 3x + 10 and

• Deepesh's age = 5x + 10

According to the question :

$\longrightarrow \sf \: \dfrac{3x + 10}{5x + 10} = \dfrac{5}{7}$

$\longrightarrow \sf \: 7(3x + 10) = 5(5x + 10)$

$\longrightarrow \sf \: 21x + 70 = 25x + 50$

$\longrightarrow \sf \: 21x - 25x = 50 - 70$

$\longrightarrow \sf \: - 4x = - 20$

$\longrightarrow \sf \: x = \dfrac{20}{4}$

$\longrightarrow \sf \: x = 5 \: years$

$\therefore$ Present age of Deepesh = 5x = 5(5) = 25 years.

Answer 2

Question= The ratio of ages of Kunal and Deepesh is 3:5. After 10 years this ratio becomes 5:7.

What is the present age of Deepesh ?

(A) 20 years

(B) 25 years

(C) 50 years

(D) 15 years

Solution⬇️

Let the age of= x

According to the question

3x+5x+10=5x+7x

8x+10= 10x

10= 12x- 8x

4x=10

x= 10/4

Age of deepesh 10/4*5

25/2 years