Permutations And Combinations Question 155

Question: A man has 10 friends. In how many ways he can invite one or more of them to a party [AMU 2002]

Options:

A) $ 10! $

B) $ 2^{10} $

C) $ 10!-1 $

D) $ 2^{10}-1 $

Show Answer

Answer:

Correct Answer: D

Solution:

  • Required number of ways = $ 2^{10} $ - 1 (Since the case that no friend be invited i.e., $ ^{10}C_0 $ is excluded).