In how many different ways can the letters of the word "ARISE"be arranged?
1). 90
2). 60
3). 180
4). 120
The word 'ARISE' has 5 different letters
=> Required number of arrangements = $5!$
= $5 \times 4 \times 3 \times 2 \times 1 = 120$
$= 5!$
= $5 \times 4 \times 3 \times 2 \times 1 = 120$