Please help me with this question. (Probability)

Question 4 The time a customer waits for hisfher order follows a normal distribution with a mean of 6 minutes and standard deviation of 1.5 minutes. (Round all percentages to 1 decimal place. e.g. 37.2%) a) What percentage of customers will wait less than 5 minutes? b) Customers get impatient if they wait more than 8 minutes. What percentage of customers will be impatient? c) Mei decides to give a free ice cream to the 5% of people who wait the longest to be served. What customer wait time (to the nearest second) marks the cut-off for receiving a free ice cream? d) Mei wants to improve the wait times. Her aim is that no more than 10% of customers wait longer than 7 minutes. If the mean waiting time remains at 6 minutes. what will the standard deviation of the wait time have to be. in order for her aim to be met? Show all steps of working. 10