A, B, C, D, and E practice running at a stadium that has several tracks. Each one starts running from the same point Z. A runs around a path which is an equilateral triangle ZYX. B runs around a square path ZYWV. C runs on a regular pentagonal path ZYUTS. D runs on a regular hexagonal path ZYRQPO. E runs along the trapezium ZYPO and completes one round in 20 seconds. Among all the tracks, there is a common side ZY, having length 100 m. The ratio of speeds of B and C is 5 : 4 respectively whereas the ratio of the time taken by A and D to complete one round of their tracks is 3 : 4 respectively. E's speed is the same as B's speed whereas A's speed is half that of C's.Note: The athletes maintain the same speeds in any track.Q 110. If E runs along the paths taken by A and B, then the time taken by him to complete 1 round each of the paths is approximately what percentage more or less than the total time taken by A and B?a) 46.24 % less timeb) 35.03 % more timec) 39.13 % less timed) 24.46 % less time
Question
A, B, C, D, and E practice running at a stadium that has several tracks. Each one starts running from the same point Z. A runs around a path which is an equilateral triangle ZYX. B runs around a square path ZYWV. C runs on a regular pentagonal path ZYUTS. D runs on a regular hexagonal path ZYRQPO. E runs along the trapezium ZYPO and completes one round in 20 seconds. Among all the tracks, there is a common side ZY, having length 100 m. The ratio of speeds of B and C is 5 : 4 respectively whereas the ratio of the time taken by A and D to complete one round of their tracks is 3 : 4 respectively. E's speed is the same as B's speed whereas A's speed is half that of C's.Note: The athletes maintain the same speeds in any track.Q 110. If E runs along the paths taken by A and B, then the time taken by him to complete 1 round each of the paths is approximately what percentage more or less than the total time taken by A and B?a) 46.24 % less timeb) 35.03 % more timec) 39.13 % less timed) 24.46 % less time
Solution
To solve this problem, we first need to calculate the perimeter of each shape, which represents the total distance each person has to run.
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For A, the path is an equilateral triangle. The perimeter of an equilateral triangle is 3 times the length of one side, so the total distance A has to run is 3*100 = 300m.
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For B, the path is a square. The perimeter of a square is 4 times the length of one side, so the total distance B has to run is 4*100 = 400m.
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For E, the path is a trapezium. We don't have enough information to calculate the exact perimeter of the trapezium, but we know that E completes one round in 20 seconds and his speed is the same as B's speed. Therefore, we can calculate E's speed as 400m/20s = 20m/s.
Now, we can calculate the time it would take E to run along the paths taken by A and B.
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For A's path, the time would be distance/speed = 300m/20m/s = 15 seconds.
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For B's path, the time would be distance/speed = 400m/20m/s = 20 seconds.
So, the total time taken by E to complete 1 round each of the paths is 15s + 20s = 35s.
Next, we need to calculate the total time taken by A and B.
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We know that A's speed is half that of C's, and C's speed is 4/5 that of B's. Therefore, A's speed is (1/2)*(4/5)*20m/s = 8m/s. So, the time taken by A is distance/speed = 300m/8m/s = 37.5s.
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The time taken by B is distance/speed = 400m/20m/s = 20s.
So, the total time taken by A and B is 37.5s + 20s = 57.5s.
Finally, we can calculate the percentage difference between the time taken by E and the time taken by A and B. The formula for percentage difference is (difference/original)*100%.
The difference is 57.5s - 35s = 22.5s. The original time is 57.5s. So, the percentage difference is (22.5s/57.5s)*100% = 39.13%.
Therefore, the answer is c) 39.13% less time.
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