Question

A 3-letter word is made from the word HAPPY. Find the probability that the word contains two letter P's.

Answer 1

order does not matter:so its a combination

ways to choose 3 out of 5 letter=
5C3=5!/(5-3)!3!=10 ways

ways to choose 2 letter p's:
2C2=1
for h=1
for a=1
for y=1

ans.= 1/10