Question

A bag has 7 red marbles, 8 blue marbles and 3 black marbles. What is the probability of picking a blue marble, replacing it, and then picking a black marble?

Answer 1

The number of sample space by which a marble can be picked without replacement can be calculated through the principles of counting.
test period = (15 x 14 x 13)
= 2730

Using the basic principles of counting, we yield an answer of,
= (8)(3) = 24

The probability is therefore the quotient of these items.
Ratio = 24/2730
Simplifying,
Ratio = 4/455