document.write( "Question 871504: Po Ling can bicycle 75 mi in the same time it takes her to drive 165 mi. If she drives 30mph faster than she bikes, how fast does she bike ? Not sure how to solve without them giving time increments. Do I just make up my own. The answer in the key is 25mph but, I cannot figure out how they came up with this figure. \n" ); document.write( "

Algebra.Com's Answer #525565 by mananth(16946) $\"\"$ $\"About$

You can put this solution on YOUR website!
Po Ling can bicycle 75 mi in the same time it takes her to drive 165 mi. If she drives 30mph faster than she bikes, how fast does she bike ? \r
\n" ); document.write( "\n" ); document.write( "Both times are same\r
\n" ); document.write( "\n" ); document.write( "cycle speed be x
\n" ); document.write( "distance = 75 miles
\n" ); document.write( "t= 75/x\r
\n" ); document.write( "\n" ); document.write( "Car speed = (x+30)
\n" ); document.write( "car distance = 165 miles\r
\n" ); document.write( "\n" ); document.write( "t= 165/(x+30)\r
\n" ); document.write( "\n" ); document.write( "165/(x+30)= 75/x\r
\n" ); document.write( "\n" ); document.write( "cross multiply
\n" ); document.write( "165x=75(x+30)\r
\n" ); document.write( "\n" ); document.write( "165x=75x+2250\r
\n" ); document.write( "\n" ); document.write( "165x-75x=2250
\n" ); document.write( "90x=2250
\n" ); document.write( "/90
\n" ); document.write( "x= 25\r
\n" ); document.write( "\n" ); document.write( "Cycle speed = 25 mph \n" ); document.write( "

\n" );