document.write( "Question 565011: A van travels for two hours at an average speed of 40 miles per hour. For how long must the van then travel at an average speed of 55 miles per hour to raise the overall average speed to 45 miles per hour? What is the total time traveled? \n" ); document.write( "
Algebra.Com's Answer #365568 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
A van travels for two hours at an average speed of 40 miles per hour.
\n" ); document.write( "1st distance = 80 miles.
\n" ); document.write( "-----------------------------------
\n" ); document.write( "For how long must the van then travel at an average speed of 55 miles per hour to raise the overall average speed to 45 miles per hour?
\n" ); document.write( "Let that time = x hrs;
\n" ); document.write( "Then distance traveled is 55x
\n" ); document.write( "-----------------------------------
\n" ); document.write( "What is the total time traveled?
\n" ); document.write( "Final average = (total distance)/(total time) = (80+55x)/(2 + x)
\n" ); document.write( "-----
\n" ); document.write( "Equation:
\n" ); document.write( "45 = (80+55x)/(2+x)
\n" ); document.write( "90 + 45x = 80 + 55x
\n" ); document.write( "10x = 10
\n" ); document.write( "x = 1 hr. (time the van traveled at 55 mph)
\n" ); document.write( "=============================================
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( "==============
\n" ); document.write( " \n" ); document.write( "
\n" );