In a race of 1000 m, John beats Khan by 120 m. If the speed of John is 40 km/h, then the speed of Khan is:
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e.35.2 km/h.
In a race of 1000 m, John beats Khan by 120 m
Distance covered by John = 1000 m
Distance covered by Khan = 1000 - 120 = 880 m
Speed of John = 40 km/hr
⇒ 40 × 5/18 = (20 × 5)/9 = 100/9 m/sec
Time taken by John = 1000/(100/9) = (1000 × 9)/100 = 900 sec
Speed of John = 880/990 = 0.97777 m/sec
⇒ 0.97777 × 15/8 = 32.5 km/hr.