If $$\frac{{3a + 5b}}{{3a - 5b}} = 5,$$   then a : b is equal to?

A. 2 : 1

B. 2 : 3

C. 1 : 3

D. 5 : 2

Answer: Option D

Solution(By Examveda Team)

$$\eqalign{ & \frac{{3a + 5b}}{{3a - 5b}} = 5 \cr & \Rightarrow 3a + 5b = 15a - 25b \cr & \Rightarrow 12a = 30b \cr & \Rightarrow 2a = 5b \cr & a:b \cr & 5:2 \cr} $$