Race and Games

Q 9: A can run 10 m while B runs 20 m. In a kilometer race B beats A by: A)400 m B)500 m C)450 m D)None of these Answer : Option B Explanation: When B runs 20 m, A runs 10 m When B runs 1000 m, A runs[(10)x(1/20)x 1000]m=500 m B beats A by 500 m Q 10: In a 200 m race A beats B by 22.5 m or 4 seconds. B's time over the course is: A)35.40 sec B)35.55 sec C)45.53 sec D)40.55 sec Answer : Option B Explanation: B runs 45/2 m in 4 sec. B covers 200 m in[4 x(2/45) x 200] sec=35.55 sec Q 11: A and B run a km race A wins by 1 minute. A and C run a km race and A wins by 200 meters. B and C run a km race and B wins By 20 seconds .Find the time that C take to run a km race. A)5 minutes 40 sec. B)6 minutes 40 sec. C)4 minutes 50 sec. D)None of these Answer : Option B Explanation: A beats B by 1 minute (60 seconds) and B beats C by 20 Seconds ∴ A beats C by ( 60 + 20) or 80 seconds But A beats C by 200 m ∴ But A runs C by 200 m. ∴ C runs 1000 m in (80/200) x 1000 = 400 seconds = 6 minutes 40 sec. Q 12: Two men A and B walk round a circle 2000 meters in circumference. A walks at the rate of 140 meters, and B at the rate 90 meters per minute .if they start from the same point, and walk in the same direction, when will they be together again ? A)50 minutes B)30 minutes C)40 minutes D)48 minutes Answer : Option C Explanation: A and B will be together again for the first time , when A has gained one complete round on B. Now A gains ( 140- 90) or 50 meters on B in 1 minute A gains 2000 meters in 2000/50 or 40 minutes.

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