Aptitude Time And DistancePage 4
25. | | How many minutes does Aditya take to cover a distance of 400 m, if runs at a speed of 20 kmph? | | (a)60 seconds | | (b)72 seconds | | (c)80 seconds | | (d)82 seconds |
|
Answer is: BAditya's speed = 20 kmph = 20 x 5/18 m/sec = 50/9 m/sec
Time taken to cover 400 m = (400 x 9/50) sec = 72 sec.
26. | | A man travelled from the village to the post office at the rate of 25 kmph and walked back at the rate of 4 kmph. If the whole journey took 5 hours 48 minutes, find the distance of the post office from the village? | | (a)18 km | | (b)21 km | | (c)20 km | | (d)22 km |
|
Answer is: CAverage speed = (2XY/X+Y) kmph = {(2 x 25 x 4)/25+4} = 200/29 kmph
Distance travelled in 5 hours 48 minutes i.e. (200/29)X(29/5) = 40 km.
Hence, Distance of the post office from the village = 40/2 = 20 km.
27. | | One of the two buses completes a journey of 300 km in 7 hours 30 minutes and the other a journey of 450 km in 9 hours. The ratio of their average speeds is? | | (a)2 : 3 | | (b)3 : 4 | | (c)4 : 5 | | (d) 8 : 9 |
|
Answer is: CRatio of speeds = (300X2/15) : (450/9) = 40 : 50 = 4 : 5
28. | | The speed of a car increase by 1 kms after every one hour. If the distance travelled in the first one hour was 35 kms, what was the total distance travelled in 12 hours? | | (a)456 km | | (b)482 km | | (c)552 km | | (d)556km |
|
Answer is: CTotal distance travelled in 12 hours = (35+37+39+ ……….upto 12 terms).
This is an A.P. with first term , a = 35 , number of terms, n = 12, common difference, d = 2.
Required distance = n/2[2a + (n-1)d] = 12/2[2x35 + (12-1)2] = 6[70 + 22] = 552 km.
29. | | A person has to cover a distance of 6 km in 45 min. If he covers 1/2 of the distance in 2/3 of the total time, to cover the remaining distance in the remaining time, his speed (in kmph) must be? | | (a)6 kmph | | (b)8 kmph | | (c)12 kmph | | (d)15 kmph |
|
Answer is: CRemaining distance = 3 km
And remaining time = 45 x 1/3 = 15 min = 1/4 hour.
Required speed = (3 x 4) kmph = 12 kmph.
30. | | Excluding stoppages, the speed of a bus is 54 kmph and including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour? | | (a)9 | | (b)10 | | (c)12 | | (d)20 |
|
Answer is: BDue to stoppages, it covers 9 km less.
Time taken to cover 9 km = (9/54) x 60 min. = 10 min.
31. | | A person travels equal distances with speeds of 3 kmph, 4 kmph and 5 kmph and takes a total time of 47 min. The total distance (in kmph) is: | | (a)2 | | (b)3 | | (c)4 | | (d)5 |
|
Answer is: BLet the total distance be X km.
Then, X/3 + X/4 + X/5 = 47/60
X = 1
Total distance = (3 x 1) km = 3 km.
32. | | A is faster than B. A and B each walk 24 km. The sum of their speeds is 7 kmph and the sum of times taken by them is 14 hours. Then, A's speed is equal to: | | (a)3 kmph | | (b)4 kmph | | (c)5 kmph | | (d)7 kmph |
|
Answer is: ALet A's speed = X kmph , Then B's speed = (7 - X) kmph
So, 24/X + 24/(7 - X) = 14
After solving the equation , we get X = 3 , 4
Since, A is faster than B, So A's speed = 4 kmph and B's speed = 3 kmph.
Comments