Question

Find the number of ways you can arrange (a) all of the letters and (b) two is the letters in the word ROCK. a. The number of ways you can arrange all of the letters in the word is __. b. The number of ways you can arrange two of the letters in the word is __.

Answer 1

a) 24

b) 12

Explanation:

a) For the 4 letters of the word ROCK

Selecting any first letter, we have 4 options

for the second, we have 3 options

for the third we have 2 options

for the fourth, we have only one option

So the number of ways will be ;

4 * 3 * 2 * 1 = 24 ways

b) 2 out of 4

For the first letter, we have 4 options, for the second, we have 3 options

so the number of options is 4 * 3 = 12 options