Discussion Forum



1)

If a + b = 5 and 3a + 2b = 20, then (3a + b) will be :


A) 10

B) 15

C) 20

D) 25

Answer:

Option D

Explanation:

Given,
a+b = 5-------(1)
3a+2b = 20----(2)
Multiply equ. (1) by 2 and subtract it from equ (3),
we get, a = 10;
Put a = 10 in equ. (1) we get, b = -5
So, 3a+b = (3 $\times$ 10) -5 = 25