Five urns contain White and Red marbles as follows: – 2 urns have contents C1: 2

ID: 2925435 • Letter: F

Question

Five urns contain White and Red marbles as follows:

– 2 urns have contents C1: 2 White, 1 Red,

–1 urn has contents C2: 10 Red,

–2 urns have contents C3: 3 White, 1 Red.

We plan to select an urn at random, and then a marble at random from the urn. Then we

will do it again (select an urn at random, and then a marble at random from that urn). What

is the probability two Red marbles will be chosen

a.) if we put the first marble back in its urn after selection?

b.) if the first marble is not replaced after selection?

P(two red marble with replacement)

P(choosing an urn) =1/5 = 0.2

P(Red|C1)=1/3

P(Red|C2)=1

P(Red|C3)=1/4

P( choosing a red marble) = 2*0.2*0.33+0.2+2*0.2*0.25=0.432

P(2 reds with replacement ) = 0.432*0.432 =0.186

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.