Question:
Two coins are tossed simultaneously. What is the probability of getting at least one head?
Solution:
GIVEN: Two coins are tossed simultaneously.
TO FIND: Probability of getting at least one head.
When two coins are tossed then the outcome will be
TT, HT, TH, HH.
Hence total number of outcome is 4.
At least one head means 1H or 2H.
Hence total number of favorable outcome i.e. at least one head is 3
We know that PROBABILITY = 
Hence probability of getting at least one head = 