Kevin but 4 bags of gravel to cover the bottom of his fish think he has a pound of gravel left over how much gravel did Kevin used to cover the bottom of his tank

(3x - 8) pounds of gravel was used to cover the bottom of sinks, where x is the weight of bag of gravel.
Step-by-step explanation:
We are given the following information in the question:
In order to answer this question we need to make the following assumption
Let x pound be the weight of one bag of gravel.
Total number of bags of gravel bought by Kevin = 3
Weight of 3 bags of gravel = 3x pounds
Amount of gravel left after pouring = 8 pounds
Amount of gravel used to cover the bottom of sink =
Formula:
Amount of gravel used to cover the bottom of sink = amount of gravel brought - amount of gravel left = 3x-8

Thus, (3x - 8) pounds of gravel was used to cover the bottom of sinks.
All but 8 pounds