an urn contain 13 balls identical in every aspect except color.

Question

help with this two part question please.

an urn contain 13 balls identical in every aspect except color. there 9-green, 3-red, 1-white ball in the urn. If you draw a ball, record the color then draw a second, what is the probability of choosing a green followed by a red ball? if you draw a ball, record the color then draw a second, what is the probability of choosing two white balls?

Answer 1

9 green, 3 red, 1 white

Probability of of choosing a green then a red:

Probability first ball is green:  9/13

Given that first ball is green, probability second ball is red:  3/12 = 1/4

Probability of green then red:  9/13 * 1/4 = 9/52 = 0.17307692307

Probability of drawing two white balls:  0.  There is only 1 white ball to draw.