Hi, can someone help me really fast on this...

Monitors manufactured by tsi electronics have life spans that have a normal distribution with a standard deviation of 1800 hours and a mean life span of 20,000 hours. if a monitor is selected at random, find the probability that the life span of the monitor will be more than 17,659 hours. round your answer to four decimal places.

Susie wants to take her friend out for lunch.she wants to spend $9.75 each person. how much will she spend in all.

Arational number that is equivalent to -20/4?