Question

The number of ways in which 20 differently coloured flowers be strung in the form of a garland is:

• A. $19!$
• B. $\frac{19!}{2!}$
• C. $20!$
• D. $21!$

Answer 1

Answer: (B)

$\frac{19!}{2!}$

Total no. of ways in which a garland can be made of n things is $\frac{(n-1)!}{2}$
$\therefore$ no. of different garlands = $\frac{(20-1)!}{2}=\frac{19!}{2}$