The probability that a wafer contains a large particle of contamination is 0.01. If it is assumed that the wafers are independent, what is the probability that exactly 125 wafers need to be analyzed before a large particle is detected

Answer: The probability of getting a large particle of contaminant in a 125 wafers is 1e-250 = 1*10^-250.

Explanation: Probability is the possible chances of an event to occurs.

The probability of a wafer to contain a large particle of contaminant is;

0.01

Because the possibility of a wafers to contain a large particle of contaminant are independent to each other, therefore the probability of 125 wafers to contain large particle of contaminant will be;

0.01^125 = 1 * 10^-250 = 1e-250

This means that it will be very difficult to identify a large particle of contaminant in 125 wafers