Mathematics

The surnames of 40 children in a class arranged in alphabetical order. 16 of the…

The surnames of 40 children in a class arranged in alphabetical order. 16 of the surnames begins with O and 9 of the surname begins with A, 14, of the letters of the alphabet do not appear as the first letter of a surname

What is the probability that the surname of a child picked at random from the class begins with either O or A?

  • A.
    5/8
  • B.
    7/8
  • C.
    9/16
  • D.
    14/25
  • E.
    39/40
Correct Answer: Option A
Explanation

No. of possible outcome = 40
No. of expected outcome = 16 + 9 = 25
Probability = 25/40 = 5/8