Question

A bag contains 7 green marbles 9 red marbles 10 orange marbles 5 brown marbles and 10 blue marbles you choose a marble replace it and choose again what is P(Red then blue)?

77/164
19/41 my answer
90/1681
45/41

Answer 1

P(R)=9/41, P(B)=10/41

P(RthenB)=P(R)*P(B)

P(RthenB)=(9/41)(10/41)=90/1681

Note:

19/41 would be the probability of P(RorB) on the first pick...