WAEC - Mathematics (1988 - No. 40)
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?
5/8
7/8
9/16
14/25
39/40
Explicação
No. of possible outcome = 40
No. of expected outcome = 16 + 9 = 25
Probability = 25/40 = 5/8
No. of expected outcome = 16 + 9 = 25
Probability = 25/40 = 5/8