Answer:
53lbs.
Step-by-step explanation:
If Kevin bought 3 20lbs. Bags of gravel he would have 60 lbs. of gravel. In the end he has 7 lbs. of gravel left he used 53 pounds.
Equations:
7+x=60 or 60-7=53 lbs.
3 pounds of gravel
If you look at the chart, each bag of gravel is 20 lbs. If he bought 4 then that is 20 x 4. That equals 80. If he only used 77 pounds of it, then you get 80-77. That equals 3
