Question 263188
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Soybean is 18% protein and cornmeal is 9% protein, how many lbs you mix for 360lbs at 16% protein?
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        The solution in the post by @mananth is incorrect due to his arithmetic error.

        See my correct solution below.



soyabean---------------- cornmeal-------------- mix
18---------------------- 9---------------------16


let quantity of soybean be x
quantity of cornmeal will be 360-x
0.18x + 0.09*(360-x) = 360*0.16
0.18x + 32.4 - 0.09x = 57.6
0.09x = 25.2
x = 25.2/0.09 = 280 lbs soybean, cornmeal 360-280 = 80 lbs.   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<<<---===  &nbsp;&nbsp;&nbsp;&nbsp;<U>ANSWER</U>


<U>CHECK</U>.  &nbsp;&nbsp;{{{(0.18*280 + 0.09*80)/360}}} = 0.16,  &nbsp;&nbsp;or &nbsp;16%.   &nbsp;&nbsp;&nbsp;&nbsp;! correct !


Solved correctly.