REPOST HELP PLEASEEE

I KNOW THIS ISNT MATH BUT NO ONE IS SEEING IT

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?

Gabrielle's age is two times mikhail's age. the sum of their ages is 84. what is mikhail's age?

The angle of elevation from point a to the top of a cliff is 38 degrees . if point a is 80 feet from the base of the cliff , how high is the cliff ?