Question

A bag of marbles contains 2 white, 3 black, 1 red and 4 blue marbles. Cate draws one marble from the bag, looks at it and then replaces it. What is the probability that she will draw a black marble and then a black marble?

A) 9/10
B) 9/100
C) 3/5
D) 1/25​

Answer 1

Explanation:

Number of black marbles = 3

Total number of marbles = 2 + 3 + 1 + 4 = 10

P(Drawing a black marble) = 3/10

Since the drawing is replaced,

they are considered independent events.

=> P(Black marble, following by black)

= [P(Drawing a black marble)]²

= (3/10)²

= 9/100. (B)