Maths Problems

Please provide answers to the below set of questions.

1. A sum of `8550 is to be paid in 15 installments where each installment

2. A salesman is known to sell a product in 3 out of 5 attempts. While another salesman in 2 out of 5 attempts. Find the probability that a. No sales will happen b. Either of them will succeed in selling the product

3. A hundred squash balls are tested by dropping from a height of 100 inches and measuring the height of the bounce. A ball is “fast” if it rises above 32 inches. The average height of bounce was 30 inches and the standard deviation was ¾ inches. What is the chance of getting a “fast” standard ball?