You are given a math word problem and you are supposed to apply a single mathematical operator like addition, subtraction, multiplication, or division on the numbers embedded in the text to answer the following question and then only report the final numerical answer.

mrs. hilt saw 33 butterflies . some of the butterflies were red and others were orange . if 20 of the butterflies were orange how many of them were red ?
13

brian has 4 more plums than paul . paul has 7 plums . how many plums does brian have ?
11

joe had 50 toy cars . if he gets 12 more cars how many cars will he have then ?
62