SSC CHSL 2020 PYQ — Question 73

SSC CHSL - 18th October 2020 - Shift 1 • Quantitative Aptitude • Q73

If 4/1+√(2)+√(3) = a + b√(2) + c√(3) – d√(6), where a, b, c, d are nature numbers, then the value of a + b + c + d is:

Show answer & explanation

Correct answer: D

Explanation

The correct answer is option 4 i.e 4.

Understanding Application
Multiply numerator and Denominator by of L.H.S by 1+√(2)-√(3) 

{4/1+√(2)+√(3)} x (1+√(2)-√(3))/(1+√(2)-√3) = a + b√(2) + c√(3) – d√(6)

{4 x (1+√2-√3)}/{(3 + 2√2) - (√3)2} =a +  b√(2) + c√(3) – d√(6)

{4 x (1+√2-√3)} / 2√2 = a +  b√(2) + c√(3) – d√(6)

2 + √2 - √6 = a +  b√(2) + c√(3) – d√(6)

By comparing both sides.

a = 2, b = 1, c = 0 and d = 1

Now, a + b + c + d = 2 + 1 + 0 + 1 = 4

So the value of a + b + c + d = 4