In an 800 m race, the ratio of the speeds of two contestants Alka and Mira is 4 : 7. If Alka has a start of 520 m, then, Alka will win by:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 310 m.
Ratio of speeds of Ankur and Neha = 5 ∶ 6
Head-start for Ankur = 200 m
Total distance of race = 800 m
Distance = Speed × Time
Let the speed of Ankur be 5 units and the speed of Neha be 6 units
Time taken by Ankur to complete 600 m race as head start given to him,
600 = 5 × Time
⇒ Time taken by Ankur = 120 units
Distance covered by Neha in 120 units of time,
⇒ 120 × 6
⇒ 720 m
Neha loses the race by,
⇒ 800 m - 720 m = 80 m