Question 647921: In a race of 1000m, Jacqui finishes 110m ahead of Lisa and 180m ahead of Fran. If Lisa and Fran continue at the same rates, how far in front of Fran will Lisa finish? (The answer is not 80m).
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! In a race of 1000m, Jacqui finishes 110m ahead of Lisa and 180m ahead of Fran.
If Lisa and Fran continue at the same rates, how far in front of Fran will Lisa
finish?
:
Assume a time for Jac to run the race, 100 seconds
:
In 100 sec Lisa runs (1000-110) 890 meters
:
Find Lisa's speed: 890/100 = 8.9 m/sec
:
Find how long it takes Lisa to run 1000 m, finish the race
1000/8.9 = 112.36 seconds
:
Find Fran's speed; 1000-180 = 820 m; 820/100 = 8.2 m/sec is Fran's speed
:
Find how far Fran has run when Lisa crossed the finish line in 112.36 sec
8.2*112.36 = 921.35 m
therefore
1000-921.35 = 78.65 m Fran is behind, when Lisa finishes
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