Question

Mr. Gray's class is conducting an experiment to find the probability of pulling certain colors from a bag of 25 marbles. If 7 are purple, 6 are yellow, 5 are green, and the rest are black, what is the probability of drawing a green and black if the marbles are not replaced after they are picked?

a.1/24
b.49/600
c.7/120
d.7/125

Answer 1

25 total marbles

7 are purple, 6 are yellow, 5 are green, the rest are black

So the # of black marbles = 25 - 7 - 6 - 5 = ?

From there, what is the probability of drawing a green and black if the marbles are not replaced after they are picked? —> first find the probability of getting green (# of green)(total # of marbles)

Then black. However, since there’s no replacement, the total # of marbles decreases by 1 since you’ve already picked one. (# of black)/(total # - 1)

Multiply the two probabilities together