Question

How many of the words formed by the letters in petrol do not begin with p?

Answer 1

total words formed is 5!
words formed from p is 4! then words not formed from p is
5!-4! =96

Answer 2

600 ways the letters in petrol do not begin with p

EXPLANATION:

There are 6 letters in the word PETROL and these letters could be arranged by taking all at one time in $=6_{P_{6}}$ ways

$=6 \times 5 \times 4 \times 3 \times 2 \times 1$

= 720 ways

Now, if a word starts with P, then P is fixed and the other 5 letters could be arranged in $= 5_{P_{5}}$ ways.

$=5 \times 4 \times 3 \times 2 \times 1$

= 120 ways

Hence, the required no of words that does not start with P are  

= 720-120

= 600 ways