Question 312855
How many pounds of 7% fat hamburger must be mixed with 30 pounds of 15% fat hamburger to obtain a 10% fat mixture? 
.
Let x = pounds of 7% fat hamburger added
then
.07x + .15(30) = .10(x+30)
.07x + 4.5 = .10x+3
4.5 = .03x+3
1.5 = .03x
50 pounds = x