Question

chester builds and collects models of boats and planes. He has 22 models altogether. Chester has 8 more planes than he does boats. How many of each kind of model does he have?

Answer 1

2 kinds of models, boats and planes. You don't know how many models he has of each so it would be:

2x
He has 8 more than of the others
2x + 8
22 total

2x + 8 = 22
2x = 14 (subtract 8)
x = 7 (boats)

Since he has 8 more planes

x + 8 = planes
(7) + 8 = 15
15 planes; 7 boats