SOLUTION: In a mixture of concrete, there are 3 lb of cement mix for each pound of gravel. If the mixture contains a total of 140 lbs of these two ingredients, how many pounds of gravel are
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Question 9517: In a mixture of concrete, there are 3 lb of cement mix for each pound of gravel. If the mixture contains a total of 140 lbs of these two ingredients, how many pounds of gravel are there? Answer by DWL(56) (Show Source):
You can put this solution on YOUR website! Let:
x = Cement
y = Gravel
x + y =140
We also know that the cement is 3 times as much as the gravel, so:
x = 3y
So now substitute in the equation x + y = 140 and it becomes:
Combine Terms
Divide both sides by 4
so the Gravel weighs 35 pounds. We know there is 3 pounds of cement for every pound of gravel, so"
so the cement = 105.
Answer"
35 Lbs. of Gravel
105 Lbs. of Cement
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