Answer:
72
Step-by-step explanation:
Step 1: Figure out percentages of what he owns
360(0.4) = 144 models he made
360 - 144 = 216 models he bought.=
Step 2: Figure out percentages of what he donated
144(0.25) = 36 models he donated (he made)
216(0.5) = 108 models he donated (he bought)
Step 3: Find the difference
108 - 36 = 72
And we have our answer!
