Mr. Smith is painting the wall but not the door. A gallon of paint will cover 200 square feet. How many gallons of paint will Mr. Smith need to purchase?

Alright so let’s find the area of the whole wall first including the door

18x12=216 sq ft

Then we find the area of the door 7x3= 21

Then subtract that from the area of the whole wall 216-21= 195 sqft

Only 1 gallon of paint will be needed since 195 is less then 200!!

Hope this helps! :)