document.write( "Question 359367: A motorist travels 90 miles at a rate of 20 miles per hour. If he returns the same distance at an average rate of 40 miles per hour, what is his average speed for the entire trip, in miles per hour? \n" ); document.write( "

Algebra.Com's Answer #256574 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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A motorist travels 90 miles at a rate of 20 miles per hour.
\n" ); document.write( " If he returns the same distance at an average rate of 40 miles per hour,
\n" ); document.write( " what is his average speed for the entire trip, in miles per hour?
\n" ); document.write( ":
\n" ); document.write( "Let a = average speed for the trip
\n" ); document.write( ":
\n" ); document.write( "Write a time equation, time = dist/speed
\n" ); document.write( ":
\n" ); document.write( "Go time + return time = total time
\n" ); document.write( " $\"90%2F20\"$ + $\"90%2F40\"$ = $\"180%2Fa\"$
\n" ); document.write( ":
\n" ); document.write( "Multiply by 40a to clear the denominators, then solve for a \n" ); document.write( "

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