ECAT Engineering Exams Quizzes MCQs Quizzes ECAT Engineering Entry Test 2017 Mathematics Induction and Binomial Theorem

Question:
In the expansion of (a – 2b)³ the coefficient of b² is

Option A):
-4a
Option B):
-8a
Option C):
-2a²
Option D):
12a

Correct Answer is Option D):
12a