Question

An athlete running on a track falls short of the finish line by 20m when she runs at a constant speed for a given time. if she increases her speed by 40%, she overshoots by 10min in the same time. what is the length of the track?

• A. 85 m
• B. 90 m
• C. 95 m
• D. 100 m

Answer 1

Answer:

C. 95 m

L = x 100% = x-20 140% = x + 10 (x+10)100 = (x-20)140 100x+1000=140x-2800 140x - 100x = 1000+2800 40x=3800 x=3800/40=95 m