Binomial Theorem And Its Simple Applications Question 33

Question: The remainder when $ 27^{40} $ is divided by 12 is

Options:

A) 3

B) 7

C) 9

D) 11

Show Answer

Answer:

Correct Answer: C

Solution:

  • [c] $ 27^{40}=3^{120} $

$ 3^{119}={{(4-1)}^{119}}={{,}^{119}}C_04^{119}-{{,}^{119}}C_14^{118} $

$ {{+}^{119}}C_24^{117}-{{,}^{119}}C_34^{116}+…+(-1) $

$ \therefore 3^{119}=4k-1 $

$ \therefore 3^{120}=12k-3=12(k-1)+9 $

$ \therefore $ The required remainder is 9.