Binomial Theorem 1 Question 13

14.

The coefficient of t4 in the expansion of (1t61t)3 is

(a) 12

(b) 10

(c) 15

(d) 14

Show Answer

Answer:

Correct Answer: 14. (c)

Solution:

  1. Clearly, (1t61t)3=(1t6)3(1t)3

Coefficient of t4 in (1t6)3(1t)3

= Coefficient of t4 in (1t183t6+3t12)(1t)3

= Coefficient of t4 in (1t)3

=3+41C4=6C4=15

( coefficient of xr in (1x)n=n+r1Cr)



NCERT Chapter Video Solution

Dual Pane