document.write( "Question 1176879: Hi
\n" ); document.write( "Joe and Bob took part in a race. When Bob had completed the race in 30min, Joe ran only 4/7 of the distance. Joe's average speed for the race was 80m per minute less than Bob's average speed.
\n" ); document.write( "Find the distance of the race.
\n" ); document.write( "What was Joe's speed in km per hour.\r
\n" ); document.write( "\n" ); document.write( "Thanks \n" ); document.write( "
Algebra.Com's Answer #804991 by 1931(1)\"\" \"About 
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Let the avg speed of Joe is x km/hr then avg speed of Bob = x+80 km/hr
\n" ); document.write( " and the d is the distance of race
\n" ); document.write( "Bob had completed the race in 30 min
\n" ); document.write( "Thus d=(x+80)/2..............(1)
\n" ); document.write( "Distance covered by Joe in 30 min
\n" ); document.write( "= x/2 =4/7*d
\n" ); document.write( "x/2= 4/7* (x+80)/2
\n" ); document.write( "x/2=2(x+80)/7
\n" ); document.write( "7x=4(x+80)
\n" ); document.write( "7x=4x+320
\n" ); document.write( "3x=320
\n" ); document.write( "x=320/3\r
\n" ); document.write( "\n" ); document.write( "Thus Joe's speed =106.66 km/hr\r
\n" ); document.write( "\n" ); document.write( "From(1)
\n" ); document.write( "d=(106.66+80)/2
\n" ); document.write( "=186.66/2=93.33 km\r
\n" ); document.write( "\n" ); document.write( "Thus Distance of race= 93.33 Km\r
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