Mathematics

The table above shows the number of pupils in each age group in a class….

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