SSC CGL 2020 PYQ — Question 89

The correct answer is option 3 i.e. 3

11 - 3$\sqrt8$ can be written as ( 9 + 2 - 2 × 3 × $\sqrt2$) 

= (3 -$\sqrt2$)²

= $\sqrt{11 - 3\sqrt8}$ = (3 -$\sqrt2$)

(3 -$\sqrt2$) =  a + b√2

On comparing we get,

a = 3 and b = -1.

(2a + 3b) = 2 × 3 + 3 × -1 = 3.