Define a variable, write an inequality, and solve each problem. check your solution.
1. half of a number is at least 14
2. the opposite of 1/3 a number is greater than 9
3. 1/5 of a number is at most 30

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?