If a number is chosen at random from the set {x: 4 (leq x leq 45)}. Find the probability that it is a multiple of 3 or a multiple of 4
-
A.
(frac{1}{12}) -
B.
(frac{5}{12}) -
C.
(frac{7}{2}) -
D.
(frac{11}{12})
Correct Answer: Option C
Explanation
set = 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
multiple of 3 = 6, 9, 12, 15
multiple of 4 = 4, 8, 12
Prob(multiple of 3 or 4) = Prob(multiple of 3) + pro(multiple of 4)
= (frac{4}{12} + frac{3}{12} = frac{7}{2})