Permutations And Combinations Question 257

Question: Six identical coins are arranged in a row. The number of ways in which the number of tails is equal to the number of heads is

Options:

A) 20

B) 9

C) 120

D) 40

Show Answer

Answer:

Correct Answer: A

Solution:

  • Required number of ways $ =\frac{6\ !}{3\ !\ 3\ !}=\frac{720}{6\times 6}=20 $ . [No. of heads $ =3 $ , no. of tails =3 and coins are identical]