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?
- A.27/40
- B.17/20
- C.3/30
- D.33/40
Correct Answer: Option B
Explanation
P(At least 11 yrs) = P(11yrs) + P(12yrs)
= 27/40 + 7/40
= 34/40
= 17/20