Question

The ages of A and B are in the ratio 3:5. If after 5 years their ages will be in the ratio 2:3, then the present age of B (in years) is
a) 30 b. 25 c) 15
d. 20
c. 15
a. 30
the smaller angle is​

Answer 1

Step-by-step explanation:

The present age of A = 3x

The present age of B = 5x

After 5 years

Age of A = 3x + 5

Age of B = 5x + 5

3x + 5 / 5x + 5 = 2 / 3

3(3x + 5 ) = 2 ( 5x +5 )

9x + 15 = 10x + 10

15 - 10 = 10x - 9x

x = 5

Present age of B = 5x = 5× 5 = 25

Answer 2

Given:-

• The ages of A and B are in the ratio 3:5.
• If after 5 years their ages will be in the ratio 2:3.

To Find:-

• Find the present age of B =?

Solution:-

Let the age of A be 3x.

Let the age of B be 5x.

Now,we had to say that after 5 years their ages will be in the ratio 2:3.

According to the question:

$\sf \implies \frac{3x +5 }{5x + 5} = \frac{2}{3} \\ \\ \sf \implies \: 3(3x + 5) = 2(5x + 5) \\ \\ \sf \implies \: 9x + 15 = 10x + 10 \\ \\ \sf \implies15 - 10 = 10x - 9x \\ \\ \sf \implies \therefore \: x = 5$

Hence, x is equal to 5.

• Present age of A = 3x = 3× 5 = 15 years
• Present age of B = 5x = 5 ×5 = 25 years

But here we said to find Present age of B = 25 years.

Option (B) is correct.