If you are wanting to use tables to solve the problems,

remember for the standard normally distributed variable with and , .

Let X be the distance the golf ball travels.

So, (1):

Now you can find this probability - the event the ball goes further than allowed.

For number (2), this requires the binomial distribution. Let Y be the event a ball goes further than allowed. The number of trials, n, is 5, and we want , where

(3) We want

Now as in Q1, convert this to a probability for . Now looking at a normal distribution table, we can see .

Now you will have an equation of the form where you know and so you can find

Can you take it from here?