SOLUTION: How many pounds of extra-lean hamburger that is 7% fat must be mixed with 30 pounds of hamburger that is 15% fat to obtain a mixture that is 10% fat?

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: How many pounds of extra-lean hamburger that is 7% fat must be mixed with 30 pounds of hamburger that is 15% fat to obtain a mixture that is 10% fat?      Log On


   



Question 145486This question is from textbook College Algebra
: How many pounds of extra-lean hamburger that is 7% fat must be mixed with 30 pounds of hamburger that is 15% fat to obtain a mixture that is 10% fat? This question is from textbook College Algebra

Found 2 solutions by solver91311, josmiceli:
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!
Pounds of extra lean: x
Pounds of regular: 30
Total weight of hamburger after the mixture has been made: x%2B30

Weight of the fat in the extra lean: 0.07x
Weight of the fat in the regular: 0.15%2A30=4.5
Weight of the fat in the total: 0.10%28x%2B30%29

The weight of the fat in each of the components of the mixture must add up to the weight of the fat in the total mix, so:

0.07x%2B0.15%2830%29=0.10%28x%2B30%29. Just solve for x to get your answer.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let x= pounds of extra-lean hamburger to be added
In words:
(pounds of fat in the extra-lean) + (pounds of fat in reg hamburger)
divided by total pounds of meat = 10% fat mixture
%28.07x+%2B+.15%2A30%29+%2F+%28x+%2B+30%29+=+.1
multiply both sides by x+%2B+30
.07x+%2B+4.5+=+.1%2A%28x+%2B+30%29
.07x+%2B+4.5+=+.1x+%2B+3
.03x+=+4.5+-+3
.03x+=+1.5
x+=+50
50 lbs of extra-lean hamburger must be used
check:
%28.07x+%2B+.15%2A30%29+%2F+%28x+%2B+30%29+=+.1
%28.07%2A50+%2B+.15%2A30%29+%2F+%28x+%2B+30%29+=+.1
%283.5+%2B+4.5%29+%2F+%2850+%2B+30%29+=+.1
8+%2F+80+=+.1
.1+=+.1
OK