Question

Mrs. Moore's class is conducting an experiment to find the probability of pulling certain colors from a bag of 25 marbles. If 7 are purple, 7 are yellow, 6 are green, and the rest are black, what is the probability of drawing 2 black if the marbles are not replaced after they are picked? Show answer as a percent rounded to nearest hundredth, if necessary.

Answer 1

This is similar to your other one

Calculate (# of black marbles) / (# of total marbles) for the first one picked

Another black marble gets picked without replacement. You’ve already picked a black marble, so subtract 1 from the black marble count as well as the total count

Calculate (# of black marbles - 1) / (total # - 1)

Multiply the two probabilities