document.write( "Question 1198083: Grapefruit costs 50 cents per 12 ounce can, and pineapple costs 85 cents per 12 ounce can. How many of each should she mix to obtain 84 ounces of a mixture that will cost 70 cents for every 12 ounces? \n" ); document.write( "
Algebra.Com's Answer #831614 by greenestamps(13200)\"\" \"About 
You can put this solution on YOUR website!


\n" ); document.write( "The response from the other tutor shows a standard algebraic solution method.

\n" ); document.write( "Here is a much faster and easier way to solve any 2-part mixture problem like this -- if you understand it, and if a formal algebraic solution is not required.

\n" ); document.write( "Look at the three costs per 12 ounces -- 50, 70, and 85 -- (on a number line, if it helps) and observe/calculate that 70 is 20/35 = 4/7 of the way from 50 to 85.

\n" ); document.write( "That means 4/7 of the mixture must be the higher priced ingredient. So...

\n" ); document.write( "ANSWERS:
\n" ); document.write( "pineapple: (4/7) of 84 ounces = 4*12 = 48 ounces
\n" ); document.write( "grapefruit: (3/7) of 84 ounces = 3*12 = 36 ounces

\n" ); document.write( "CHECK:
\n" ); document.write( "48(85)+36(50) = 4080+1800=5880
\n" ); document.write( "84(70) = 5880

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