Question

How many permutations can be made of the letters of the word "radar" when taken all at a time?

Answer 1

Slot method
5 letters
1st slot=5 options
2nd slot=4 options (1 went ot first slot)
3rd slot=3 options (1 went to 2nd)
4th slot=2 options
5th slot=1 option

5*4*3*2*1=120 ways

Answer 2

Answer:

Total number of permutations which can be made = 120

Step-by-step explanation:

The word is given to be : RADAR

Number of letters in the given word = 5

The letters are taken all at a time

⇒ Repetition of the letters are not allowed

Now, Number of possibilities for the first letter = 5

Number of possibilities for the second letter = 4

Number of possibilities for the third letter = 3

Number of possibilities for the forth letter = 2

Number of possibilities for the five letter = 1

Hence, Total number of permutations which can be made = 5 × 4 × 3 × 2 × 1  

= 120