document.write( "Question 710631: We have 2 varieties of concrete that we can mix. One is 1 part water to 3 parts concrete mix, and the other is 1 part water to 5 parts concrete mix. We want to end up with 30 lbs of a result that is 1 parts water and 4 part concrete. Determine how many pounds of each variety we need. \n" ); document.write( "
Algebra.Com's Answer #437110 by srinivas.g(540)\"\" \"About 
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first variety : portion of water = 1/4 (since ratio = 1:3 total 4 parts)
\n" ); document.write( "second variety : portion of water = 1/6 (since ratio = 1:5 total 6 parts)
\n" ); document.write( " mix : portion of water = 1/5 (since ratio = 1:4 total 5 parts)
\n" ); document.write( "
\n" ); document.write( " 1/4 1/6
\n" ); document.write( " \r
\n" ); document.write( "\n" ); document.write( " 1/5
\n" ); document.write( " proportion of first variety = (1/5 - 1/6 ) = 1/30
\n" ); document.write( " proportion of first variety = (1/4 - 1/5 ) = 1/20
\n" ); document.write( " ratio in which first variety and second variety to be mixed = 1/30 : 1/20
\n" ); document.write( " =2:3
\n" ); document.write( " total volume of the mix = 30 lbs
\n" ); document.write( " volume of the first variety int the mix = 2/5 *(30 )
\n" ); document.write( " =12 lbs
\n" ); document.write( " volume of the second variety int the mix = 3/5 * 30
\n" ); document.write( " = 18 lbs \n" ); document.write( "
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