document.write( "Question 586694: Ricardo runs 10 miles each Saturday. If he doubles his usual speed, he can run the 10 miles in one hour less than his usual time. What is his usual speed? \n" ); document.write( "

Algebra.Com's Answer #373875 by ad_alta(240) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let 'x' be his usual speed and 'h' his usual time. Then 2x*(h-1)=10 and 10=x*h, so substituting we get 2x*(10/x-1)=10. Thus, -2x+20=10 and x=5 mph. \n" ); document.write( "

\n" );