Question

If  \(\frac{a}{b} = \frac{7}{9}, \frac{b}{c} = \frac{3}{5}\) , then the value of a : b : c is
1. 7 : 3 : 15
2. 21 : 27 : 42
3. 7 : 9 : 15
4. 7 : 9 : 5

Answer 1

Correct Answer - Option 3 : 7 : 9 : 15

Given: 

\(\frac{a}{b} = \frac{7}{9}, \frac{b}{c} = \frac{3}{5}\) 

Calculation:

a/b = 7/9

Let the value of a be 7x and b be 9x.

⇒ b/c = 3/5

Let the value of b be 3y and c be 5y.

We know that value of b will be same.

⇒ 9x = 3y

⇒ x/y = 1/3

Put x = 1 and y = 3

⇒ a = 7x =7, b = 9x = 9, c = 5y = 15

∴ The value of a : b : c = 7 : 9 : 15