Question

There are 100 trading cards in a bin. They include 5 rare cards, 35 limited cards, and the remainder are common cards. Which of the following correctly interprets the probability of choosing 2 rare cards from the bin? Assume that the cards are pulled without replacement.


Select an answer

A.
5/100∙4/99


B.
5/100


C.
5/100∙5/100


D.
5/100+5/100

Answer 1

A.

P(1st rare) = 5/100. Given that happened (no replacement), P(2nd rare) = 4/99. Multiply for both: (5/100)(4/99) = 20/9900 = 1/495 ≈ 0.00202.