A *** 10 has five whites, so you must take the white one from the first time to the fifth time, so multiply the probability of taking the white one for the first time by the probability of taking the white one for the second time ... and then multiply it by the probability of taking the white one for the fifth time to get the probability.

The probability of going white for the first time is 5/ 10.

The probability of the second white is 4/9.

By analogy, the probability of winning the third place is 3/8.

The fourth 2/7

Multiply these numbers by 1/6 for the fifth time.

The second product with four white sheets in 30 yuan is the same as the first one, and so is the third one.