Question

$\frac{8a+2b}{8a-2b}=\frac{7}{1}$, then b : a =

• A. 3 : 1
• B. 4 : 9
• C. 9 : 18
• D. 25 : 1

Answer 1

The correct option is A

3 : 1

$\frac{8a+2b}{8a-2b}=\frac{7}{1}$

$\frac{8a+2b+8a-2b}{8a+2b-8a+2b}=\frac{7+1}{7-1}$ [Applying componendo and dividendo]

$\frac{16a}{4b}=\frac{8}{6}$

$4\frac{a}{b}=\frac{4}{3}$

$\frac{a}{b}=\frac{1}{3}$

$\frac{b}{a}=\frac{3}{1}$ (Applying invertendo)