SOLUTION: You are making 10 tons of concrete that is 61.1% cement by mixing a 19% cement mixture with a 90% cement mixture. a) how much of the 90% cement mixture must you use ? answer in

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Question 295216: You are making 10 tons of concrete that is 61.1% cement by mixing a 19% cement mixture with a 90% cement mixture.
a) how much of the 90% cement mixture must you use ? answer in units of tons.
b) how much of hte 19% cement mixture must you use ? answer in units of tons.
Thank you in advance for your help !

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
You are making 10 tons of concrete that is 61.1% cement by mixing a 19% cement
mixture with a 90% cement mixture.
:
a) how much of the 90% cement mixture must you use ? answer in units of tons.
Let x = amt of 90% cement mixture
then
(10-x) = amt of 19% cement mixture
:
The mixture equation
.90x + .19(10-x) = .611(10)
.90x + 1.9 - .19x = 6.11
.90x - .19x = 6.11 - 1.9
.71x = 4.21
x = 4.21%2F.71
x = 5.93 tons of 90% cement
;
b) how much of hte 19% cement mixture must you use ? answer in units of tons.
10 - 5.93 = 4.07 tons of 19% cement
:
:
Check solution in the mixture equation
.90(5.93) + .19(4.07) = .611(10)
5.337 + .7733 = 6.11