Within this I calculated the probability he pulls up a purple marble out third and when he picks it up at 7th, but the probabilities do not match.

The probability for Quantity A is:

P(A)=8/12×7/11×4/10=28/165 which is 0.169

However for Qty B, the final expression is

8/12 x 7/11 x 6/10 x 5/9 x 4/8 x 3/7 x 4/6 = 2/99 which is 0.02.

The given answer is that both are equal.

I wanted to ask if there’s any mistake I’m making and why is the answer coming out different?