Find the number of permutations of the first 8 letters of the alphabet taking four letters at a time. a.1680 b.56 c.6720 d.109

Question

asked Jul 5, 2018 26.6k views

2 Answers

Rene Schulte · Answer 1 · 2018-07-12T16:22:34+0000

Answer: a.1680

Explanation:

The number of permutations of n things taking m at a time is given by :-

P^n_m=(n!)/((n-m)!)

Similarly, the number of permutations of the first 8 letters of the alphabet taking four letters at a time will be :-

$P^8_4=(8!)/((8-4)!)\\\\=(8*7*6*5*4!)/(4!)\\\\=1680$

Hence, the number of permutations of the first 8 letters of the alphabet taking four letters at a time =1680