Make it in a paper by hand step by step pleasee

At the Tecsufone company, it was determined that the time it takes technicians to assemble a digitizer is normally distributed with a mean of 72 minutes and a standard deviation of 6 minutes. a) If one of these technicians is randomly selected, find the probability that he assembles a digitizer between 64 and 70 minutes. b) What is the time to assemble a digitizer to consider a technician in the group of the fastest 10%