The table above shows the number of pupils in each age group in a class. What is the probability that a pupil chosen at random is at least 11 years old?
- 27/40
-
17/20
- 3/30
- 33/40
The correct answer is: B
Explanation
P(At least 11 yrs) = P(11yrs) + P(12yrs)
= 27/40 + 7/40
= 34/40
= 17/20
There is an explanation video available .