document.write( "Question 1115563: An inlet pipe can fill a tank in 15 minutes. A drain can empty the tank in 20 minutes. If the tank is empty, and both the pipe and drain are open, how long will it take before the tank overflows? \n" ); document.write( "
Algebra.Com's Answer #730406 by ikleyn(52781)\"\" \"About 
You can put this solution on YOUR website!
.
\n" ); document.write( "
\r\n" );
document.write( "The inlet pipe fills  \"1%2F15\"  of the tank volume per minute.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "The drain pipe empties  \"1%2F20\"  of the tank volume per minute.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "So, the net inflow to the tank is the positive difference  \"1%2F15-1%2F20\" = \"4%2F60-3%2F60\" = \"1%2F60\" of the tank volume per minute.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "It means that the tank will be filled in 60 minutes = 1 hour if both pipes are open.\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( "It is a typical and standard joint work problem.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "There is a wide variety of similar solved joint-work problems with detailed explanations in this site.  See the lessons\r
\n" ); document.write( "\n" ); document.write( "    - Using Fractions to solve word problems on joint work \r
\n" ); document.write( "\n" ); document.write( "    - Solving more complicated word problems on joint work \r
\n" ); document.write( "\n" ); document.write( "    - Selected joint-work word problems from the archive \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Read them and get be trained in solving joint-work problems.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Also,  you have this free of charge online textbook in ALGEBRA-I in this site\r
\n" ); document.write( "\n" ); document.write( "    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The referred lessons are the part of this textbook under the topic
\n" ); document.write( "\"Rate of work and joint work problems\"  of the section  \"Word problems\".\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Save the link to this online textbook together with its description\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Free of charge online textbook in ALGEBRA-I
\n" ); document.write( "https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "to your archive and use it when it is needed.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );