I need help with this problem:
Barney can perform 45 sit-ups in one minute. Carrie can do twice as many sit-ups per minute as Barney can.  And Jerrie can do 5 more sit-ups per minute than Carrie can do.  If Barney does sit-ups for 1 minute, and Carrie does sit-ups for two minutes, and Jerrie does sit-ups for three minutes, what would be the combined total number of sit-ups performed?