Which postulate if any is this ?

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?

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 ?

The taxi fare in gotham city is $2.40 for the first 1 2 12 mile and additional mileage charged at the rate $0.20 for each additional 0.1 mile. you plan to give the driver a $2 tip. how many miles can you ride for $10?