document.write( "Question 319040: A jar contains 10 red marbles and 30 green ones. How many more red marbles must be added to the jar so that 60% of the marbles will be red? \n" ); document.write( "

Algebra.Com's Answer #228385 by Fombitz(32388) $\"\"$ $\"About$

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The ratio of red to the total is $\"R%2F%28R%2B30%29\"$ where R is the number of red marbles.
\n" ); document.write( " $\"R%2F%28R%2B30%29=60%2F100\"$
\n" ); document.write( " $\"100R=60%28R%2B30%29\"$
\n" ); document.write( " $\"100R=60R%2B1800\"$
\n" ); document.write( " $\"40R=1800\"$
\n" ); document.write( " $\"R=45\"$
\n" ); document.write( "You need to have 45 marbles in the jar to have 60% red.
\n" ); document.write( "You currently have 10 marbles.
\n" ); document.write( " $\"N=45-10=35\"$
\n" ); document.write( "You need to add $\"highlight%2835%29\"$ red marbles. \n" ); document.write( "

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