If you have to wait 20 minutes when 150 people are in line, you will have to wait 10 minutes for 75 people, and 2 minutes for 15 people. I divided both numbers by two to finding out the simplest form, but it didn't help. I went back and divided by numbers by 10 to get 2 minutes for 15 people. Since you would wait 4 minutes for 30 people. You would also wait 20 minutes for 150 people, and 32 minutes for 240 people.