document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=185180>Question 185180</A>: <I><SPAN STYLE=\"word-break: break-all;\"> please help me solve this word problem please thank you\r<BR>\n" );
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document.write( "	With only the small valve open, all of the liquid can be drained from a large vat in 4 hours.  With only a large valve open, all of the liquid can be drained from the same vat in 2 hours.  How long would it take to drain the vat with both valves open? </SPAN>\n" );
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document.write( "With only the small valve open, all of the liquid can be drained from a large vat in 4 hours. With only a large valve open, all of the liquid can be drained from the same vat in 2 hours. How long would it take to drain the vat with both valves open?<BR>\n" );
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document.write( "This type of problem comes up often.<BR>\n" );
document.write( "You have to find a common measurement to add the 2 components.  Adding the 2 and 4 for 6 doesn't work.  It's obvious it will be less than 2 hours.2 <BR>\n" );
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document.write( "The \"trick\" is to invert the times per vat to get work per hour.  One valve does 1/2 of the vat per hour, the other does 1/4 per hour.<BR>\n" );
document.write( "Add 1/2 adn 1/4 = 3/4 vat per hour together.<BR>\n" );
document.write( "Then the inverse of that is 4/3 hours per vat, = 1 hour 20 minutes.<BR>\n" );
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document.write( "A shortcut is product over sum:<BR>\n" );
document.write( "2*4/(2+4) = 8/6 = 4/3 hours. </SPAN>\n" );
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