Answer:
0.0487 = 4.87%
Step-by-step explanation:
The probability of one mail being returned is 1.5% = 0.015, so the probability of the mail not being returned is 1 - 0.015 = 0.985. If we want 0 mails returned from a total of 200 mails, we have 0 mails returned (probabilitity of 0.015) and 200 mails not returned (probability of 0.985), then the final probability is calculated as follows:
Probability = (0.985)^200 * (0.015)^0 = 0.0487 = 4.87%