Question

In how many ways can five keys be put in a ring?

• A. $\frac{1}{2}4!$
• B. $\frac{1}{2}5!$
• C. 4!
• D. 5!

Answer 1

The correct option is A

$\frac{1}{2}4!$

Required number of ways $=\frac{1}{2}(5-1)!=\frac{4!}{2}$
{Since clockwise and anticlockwise are same in case of ring}