A bag contains blue and yellow marbles. Two marbles are drawn without replacement. The probability of selecting a blue marble and then a yellow marble is 0.37, and the probability of selecting a blue marble on the first draw is 0.55.

What is the probability of selecting a yellow marble on the second draw, if the first marble drawn was blue?

A) 18%

B) 20%

C) 46%

D) 67%

Question

Mathematics

Gina Nguyen

10 July, 12:08

A bag contains blue and yellow marbles. Two marbles are drawn without replacement. The probability of selecting a blue marble and then a yellow marble is 0.37, and the probability of selecting a blue marble on the first draw is 0.55.

What is the probability of selecting a yellow marble on the second draw, if the first marble drawn was blue?

A) 18%

B) 20%

C) 46%

D) 67%

+3

Answers (1)

Know the Answer?

Peter Baxter · Answer 1

blue marbles

y = yellow marbles

Sum = b+y

The chance of a blue marble being drawn first is:

b / (b+y) = 0.55

The chance of a blue marble being drawn first then a yellow next is:

b / (b+y) * y / (b+y-1) = 0.37

This can be solve easily by using a theorem of Bayes

0.37/0.55 =.67 or 67%