Turn 18 1/2 percent into a fraction. btw i tried 37/2, 185/1000, 18.5/100 didn’t work

Molly shared a spool of ribbon with 12 people. each person received 3 feet of ribbon. which equation can she use to find r, the number of feet of ribbon that her spool originally had?

Margie is practicing for an upcoming tennis tournament. her first serve is good 20 out of 30 times on average. margie wants to know the estimated probability that her first serve will be good at least four of the next six times she serves. how could she design a simulation for this scenario?

Ineed with question three. i don't understand how i'm supposed to achieve 3 marks.