# Aptitude - Races and Games - Discussion

### Discussion :: Races and Games - General Questions (Q.No.7)

7.

In 100 m race, A covers the distance in 36 seconds and B in 45 seconds. In this race A beats B by:

 [A]. 20 m [B]. 25 m [C]. 22.5 m [D]. 9 m

Explanation:

 Distance covered by B in 9 sec. = 100 x 9 m = 20 m. 45 A beats B by 20 metres.

 Muneer said: (Feb 4, 2011) Why we are taking 45 in the solution?

 Gowthami said: (Jun 7, 2011) A beats=36sec B beats=45sec so 36----45 then 1 part=45/36=5/4 B covers A in 100m race=(4/5)*100=80m so A beats B by=(total distance)100-B covers(80) 20m faster than B

 Himanshu Singla said: (Sep 22, 2012) Here it is given that A can cover 100m in 36 sec and B in 45 sec. So when A reaches finish point B still has 9 sec left of his time to reach the final point. In this time he can cover the remaining distance by which he has been beaten. In 45sec B can travel 100m. In 1sec ------------- 100/45. In 9 sec ------------ (100/45) *9=20 Answer. HOPE you UNDERSTAND. Please clarify if am wrong.

 Marimuthu said: (May 31, 2013) In 36 seconds B covers (100/45)*36 = 80 meters. In 36 seconds A covers 100 meters. So A beat B by 20 meters.

 Mridul Chakraborty said: (Nov 13, 2013) Detailed solution for easier interpretation : Speed of A = 100 (distance)/36 (Time) = 2.78 m/s. Speed of B = 100(distance)/45(Time) = 2.22 m/s. Difference in speed between A & B = 0.56 m/s < i.e. 2.78-2.22 m/s> Hence in 36 seconds in which A finishes the race, B will cover 2.22*36 = 80 meters. So A finishes the race 20m ahead of B.

 Noname said: (Mar 16, 2015) A 1sec - (100/36) m. B 1sec - (100/45) m. 1sec - A is ahead by (100/36-100/45) = 5/9 m. So, in 36s A is ahead by (5/9*36) = 20 m.

 Santhosh said: (Aug 27, 2015) 36/45*100 = 80. 100-80 = 20.

 Student said: (Nov 5, 2015) That's a great help thanks a lot!

 T.Somadatta said: (Dec 23, 2017) Speed of A = 100 (distance) /36 (Time) = 2.78 m/s. Speed of B = 100 (distance) /45 (Time) = 2.22 m/s. Difference in speed between A & B = 0.56 m/s < i.e. 2.78-2.22 m/s>. Hence in 36 seconds in which A finishes the race, B will cover 2.22*36 = 80 meters. So, A finishes the race 20m ahead of B.

 Sana said: (Jan 8, 2018) Common time difference between A and B is =(45-36)=9sec. Now, B travel distance 100m in 45sec. So 45sec ----------> 100m 9sec ------------> (9/45)*100=20m. This 20m is actual distance between A and B or A beat by B in 20m .

 Purushotham Reddy said: (May 2, 2018) 20P---28P------100P. A---- B ---- C. Here, the difference between B and c is 8 points when you calculate only for 80 Points (from B to 100). So 8 Points - 80 Points. But we need for 100 points. Then 8p -80p. 10P-100P. Hope you understand.