What is the midpoint I really need help

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?

Linda loans her friend $250 with a 5% monthly intrest rate. how much was the whole loan?

Due to bad planning, two of the local schools have their annual plays on the same weekend. while 457 people attend one, and 372 attend the other, only 104 people were able to attend both. how many people went to at least one play?