Question

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

• A. $9$
• B. $20$
• C. $40$
• D. $120$

Answer 1

Answer: (B)

$20$

We have six coins, we know that three of them are heads. So, we can choose those three.

Which brings us to the result ${(}^6{C}_3)=\frac{6!}{3!\cdot 3!}=\frac{720}{36}=20$.