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Aptitude · Q4

Simplification

Competitive Exams · Aptitude · question 4

Q4

If a - b = 3 and a2 + b2 = 29, find the value of ab.

A.
10
Answer
B.
12
C.
15
D.
18
E.
None of these

Answer: Option A

Solution

Answer: Option A
Solution:
2ab = (a2 + b2) - (a - b)2
2ab = 29 - 9
2ab = 20
ab = 10