<PRE><B>Question 161488</B>
Soybean meal is 14% protein, cornmeal is 7% protein. How many pounds of each
 should be mixed together in order to get 280 lb mixture that is 12% protein?
:
Let x = amt of 14% protein
:
It states that the total mixture weight is 280 lb, therefore:
(280-x) = 7% protein 
;
Write a decimal equivalent equation:
.14x + .07(280-x) = .12(280)
:
.14x + 19.6 - .07x = 33.6
:
.14x - .07x = 33.6 - 19.6
:
.07x = 14
x = {{{14/.07}}}
x = 200 lb of 14% protein, then 80 lb of 7% required
:
:
Check soltution in the original equation
.14(200) + .07(80) = .12(280)
28 + 5.6 = 33.6</PRE>