Vidyalelo
Aptitude · Q8

Decimal Fraction

Competitive Exams · Aptitude · question 8

Q8

The expression (11.98 × 11.98 + 11.98 × X + 0.02 × 0.02) will be a perfect square for X equal to:

A.
0.02
B.
0.2
C.
0.04
Answer
D.
0.4

Answer: Option C

Solution

Answer: Option C
Solution:
Given expression = (11.98)2 + (0.02)2 + 11.98 × X
For the given expression to be a perfect square,
(a + b)2 = a2 + b2 + 2ab
we must have
11.98 × X = 2 × 11.98 × 0.02
∴ X = 0.04