Answer :
1800/3=600
So 600 square feet per pound
600*4=2400
So 2400 square feet per 4 pound bag
8400/2400=3.5
Answer: 3.5 Bags if it asks to round to the nearest whole bag then 4 bags
So 600 square feet per pound
600*4=2400
So 2400 square feet per 4 pound bag
8400/2400=3.5
Answer: 3.5 Bags if it asks to round to the nearest whole bag then 4 bags