document.write( "Question 1185209: In a box, there was a total of 2 353 blue and black marbles. Oliver took 3/7 of the blue
\n" ); document.write( "marbles and 455 of the black marbles. After that, the number of blue marbles left was 2/3
\n" ); document.write( "the number of black marbles left. How many black marbles were there in the box at first?\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

Algebra.Com's Answer #815991 by ikleyn(52787) $\"\"$ $\"About$

You can put this solution on YOUR website!
.
\n" ); document.write( "In a box, there was a total of 2 353 blue and black marbles. Oliver took 3/7 of the blue
\n" ); document.write( "marbles and 455 of the black marbles. After that, the number of blue marbles left was 2/3
\n" ); document.write( "the number of black marbles left. How many black marbles were there in the box at first?
\n" ); document.write( "~~~~~~~~~~~~~~~\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "

\r\n" );
document.write( "Let x be the number of black marbles, at first.\r\n" );
document.write( "\r\n" );
document.write( "Then the number of the blue marbles was  (2353-x).\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "After removong,  4/7  of the blue marbles left and  (x-455)  black marbles left.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "From the problem, we have this equation\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "     = .\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "To solve it, multiply both sides by 21 and simplify\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "    12*(2353-x) = 14*(x-455)\r\n" );
document.write( "\r\n" );
document.write( "    12*2353 - 12x = 14x - 14*455\r\n" );
document.write( "\r\n" );
document.write( "    12*2353 + 14*455 = 14x + 12x\r\n" );
document.write( "\r\n" );
document.write( "          34606      =     26x \r\n" );
document.write( "\r\n" );
document.write( "         x    =  = 1331.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "ANSWER.  There were 1331 black marbles in the box at first.\r\n" );
document.write( "

\r
\n" ); document.write( "\n" ); document.write( "Solved.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );