Answer: They can paint 18.6 ft2 with 3 gallons of paint.
Explanation:
Hi, to answer this question, first, we have to divide the square feet painted (280) by the gallons of paint used.
Mathematically speaking
280 /45 = 6.2 ft2
We have calculated the number of square feet that 1 gallon of paint can paint.
So, for 3 gallons of paint we simply multiply that result by 3.
6.2 x 3 =18.6 ft2
Feel free to ask for more if needed or if you did not understand something.