Need help with all qns thanks

The time, T, a customer waits for hisfher order follows a normal distribution with a mean of 5 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 4 minutes? b} Customers get impatient if they wait more than 7' minutes. What percentage of customers will be impatient? c} Suri 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} Suri wants to improve the wait times. Her aim is that no more than 10% of customers wait longer than 6 minutes. If the standard deviation ofthe waiting time remains at 1.5 minutes, what will ofthe average {mean) wait time have to be, in order for her aim to be met? Show all steps of working and give your answer to the nearest second