What is the area of this trapezoid?

At the newest animated movie, for every 9 children, there are 4 adults. there are a total of 39 children and adults at the movie.

Problem fathi wants to print out a pdf document that is 48 pages long. to save paper, he decides to print on both sides of each sheet and to print two pages on each side of the sheet. how many sheets of paper will he need?

What is another way to express 36 +32