In a 500 m race, P runs at 2 kmph. P gives Q a head start of 20 m and still beats him by 60 seconds. Find the speed of Q.
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 1.8 kmph.
Total distance = 500
Speed of P = 2 kmph
P gives Q a head start of 20 m and still beats him by 60 seconds.
Speed = distance/time
1 (kilometer/hour) = 1000/3600 (meters/seconds) = 5/18 m/s
According to the question,
⇒ 480/Q - 500/(2 × 5/18) = 60
⇒ 480/Q - 900 = 60
⇒ 480/Q = 960
⇒ Q= 1/2 × 18/5
⇒ Q = 1.8 Kmph