Hi really need 1, 2 and ! you all in advance! again just one, two, and three !

2-digit numbers less than 91 which are 1 less than a multiple of 10

Two airplanes start at the same place and travel in opposite directions,one at 395 miles per hour and the other at 422 miles per hour. how many hours will it take for the planes to be 2451 miles apart?

The computer that controls a bank's automatic teller machine crashes a mean of 0.6 times per day. what is the probability that, in any seven-day week, the computer will crash less than 5 times? round your answer to four decimal places