SOLUTION: In a mixture of​ concrete, there are five lb of cement mix for each pound of gravel. If the mixture contains a total of 90 lb of these two​ ingredients, how many pounds

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Question 1030336: In a mixture of​ concrete, there are five lb of cement mix for each pound of gravel. If the mixture contains a total of 90 lb of these two​ ingredients, how many pounds of gravel are​ there?
Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Almost a simple proportion.

c for amount of cement mix
g for amount of gravel
c%2Bg=90

The proportion you might want to arrange is using %285%2F1%29%28poundsCementMix%2FpoundsGravel%29. Using this ratio to set a proportion will mean you may use g as your main variable, and then c=90-g.



Upon seeing the units taken care well,
5=%2890-g%29%2Fg;
Go from there.....

Answer by ikleyn(52787) About Me  (Show Source):
You can put this solution on YOUR website!
.
In a mixture of concrete, there are five lb of cement mix for each pound of gravel.
If the mixture contains a total of 90 lb of these two ingredients, how many pounds of gravel are there?
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Group (mentally) 5 lb of cement with 1 pound of gravel.
You will get groups of cement-gravel of total weight 6 pounds each.

The number of groups is 90%2F6 = 15.

So, there are 15 lb of gravel in the mixture.