Question

A hobby shop sells 4 times as many model of airplanes than model helicopters the total number of model is 35

Answer 1

let's call airplanes "a" and helicopters "h".

The total number of models is 35. This means that a+h=35

4 times as many model airplanes as model helicopters. This means a=4h.

we can substitute this into the previous equation:

4h+h=35

5h=35

dividing by 5:

h=7

so he has 7 helicopters and 4*7=28 airplanes