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CaptainLevi
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In a 6 km long race, A beats B by 20 seconds, B beats D by 70 seconds 24 Nov 2019, 11:02
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C
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In a 6 km long race, A beats B by 20 seconds, B beats D by 70 seconds and C beats D by 40 seconds. If the speed of A is 54 km/hr, by what distance does B beat C?

(A) 360 m
(B) 380 m
(C) 400 m
(D) 380 m
(E) 500 m
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C
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In a 6 km long race, A beats B by 20 seconds, B beats D by 70 seconds 26 Nov 2019, 05:59
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CaptainLevi
In a 6 km long race, A beats B by 20 seconds, B beats D by 70 seconds and C beats D by 40 seconds. If the speed of A is 54 km/hr, by what distance does B beat C?

(A) 360 m
(B) 380 m
(C) 400 m
(D) 380 m
(E) 500 m
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We are given the speed of A only.
Time taken by A to complete the race= Distance/Speed = 6 km / 54 km/hr = (1/9)*3600 sec = 400 sec
Time taken by B to complete the race is 20 sec extra because A beats B by 20 sec. So time taken by B = 420 sec
Time taken by D to complete the race is another 70 secs so D takes 490 secs
Time taken by C to complete the race is 40 secs less than D (because C beats D by 40 secs) = 450 secs

When distance travelled is same, time taken by B : time taken by C = 420 : 450 = 14:15
When time taken is same, distance travelled by B : Distance travelled by C = 15 : 14
The distance of 15 travelled by B is actually 6 km i.e. 6000 m. This means our multiplier is 400. So the difference of 1 between the distances they travelled is 400.

Answer (C)

For more on ratios, check: https://www.gmatclub.com/forum/veritas-prep-resource-links-no-longer-available-399979.html#/2011/0 ... of-ratios/
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In a 6 km long race, A beats B by 20 seconds, B beats D by 70 seconds 24 Nov 2019, 11:43
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Answer C.

A,B,C&D completed the 6000m race with a gap of 20 sec,30 sec, & 40 sec respectively.
Now, Speed of A was 15 mtr/s therefore A took 400 sec to complete the track and B took 400+ 20 sec, similarly C took 450 sec.
With the time, calculate the speed of B and C.
With the speed, calculate the distance of C at T=420 sec(time when B completed the race), which is 5600mtr, therefore the distance between B and C is 6000-5600= 400 mtrs



Answer C.

A,B,C&D completed the 6000m race with a gap of 20 sec,30 sec, & 40 sec respectively.
Now, Speed of A was 15 mtr/s therefore A took 400 sec to complete the track and B took 400+ 20 sec, similarly C took 450 sec.
With the time, calculate the speed of B and C.
With the speed, calculate the distance of C at T=420 sec(time when B completed the race), which is 5600mtr, therefore the distance between B and C is 6000-5600= 400 mtrs
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In a 6 km long race, A beats B by 20 seconds, B beats D by 70 seconds 25 Nov 2019, 23:42
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A's speed = 54 kph = 15 m/s. The time taken by him is 6000/15=400 seconds.
B's time: 400+20=420 seconds
D's time: 420+70=490 seconds
C's time: 490-40=450 seconds

Let VA, VB and VC be the speeds of A.B and C respectively.
THE RATIO OF THE SPEEDS OF TWO MOVING OBJECTS IS EQUAL TO THE INVERSE OF THE RATIOS OF THE TIME TAKEN BY EACH TO COVER THE SAME DISTANCE. Therefore:
VA/VB=420/400.....(i)
VB/VC=450/420.....(ii)
Multiplying (i) and (ii):
VA/VC=450/400....> 15/VC=9/8....> VC=40/3 m/s
So, when B finishes the race, C is 450-420=30 seconds or 30*(40/3)= 400 meters behind. ANS: C
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In a 6 km long race, A beats B by 20 seconds, B beats D by 70 seconds 03 Mar 2021, 18:50
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(1st)
Saying that A beat C by 20 seconds means that C has 20 more seconds to travel at the Speed of C (himself) to finish the race.

Convert everything to meters and seconds.

Speed of A = 54 km/hr -or- 15 met/sec

Time of A to finish Race = (6,000 m) / (15) = 400 sec

Since A beat B by 20 seconds:

Time of B to finish race = 420 sec

(2nd)
B beats D by 70 seconds.

Time of B to finish = 420 seconds

Then Time of D to finish = 420 sec+ 70 sec = 490 sec


(3rd)
C beats D by 40 seconds.

It takes D 490 sec to finish race.

Then it takes C: Time of C to finish race = (490) - (40) = 450 sec


Summary to run 6,000 meters

Time A = 400 sec
Time B = 420 sec
Time C = 450 sec
Time D = 490 sec

“By what distance does B beat C?”

B finishes race in 420 seconds

At this point, C would still have another 30 seconds to go.


Find Speed of C:
(6,000 met) / (450 sec) = 40/3

Distance for C left to go in 30 seconds: Dist = speed * time

(40/3) m/sec * (30) sec = 400 meters


(C) 400

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In a 6 km long race, A beats B by 20 seconds, B beats D by 70 seconds 29 Jun 2022, 05:32
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A’s speed is 54 km/hr or 54*5/18 = 15m/s

Time taken by A to cover 6km = 6000/15 = 400s
Thus, B will cover this in 420s, D in 490 and C in 450s.
The ratio of the speed of B and C is 15:14

If B covers 6000m in 420 seconds, C will cover 6000*14/15m in the same time.
Thus, C will cover 5600m
The distance by which B beats C will be 400m.
Thus, the correct option is C.
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In a 6 km long race, A beats B by 20 seconds, B beats D by 70 seconds 27 Jul 2025, 11:47
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