Aptitude - Time and Distance - Discussion
Discussion Forum : Time and Distance - General Questions (Q.No. 12)
12.
Robert is travelling on his cycle and has calculated to reach point A at 2 P.M. if he travels at 10 kmph, he will reach there at 12 noon if he travels at 15 kmph. At what speed must he travel to reach A at 1 P.M.?
Answer: Option
Explanation:
Let the distance travelled by x km.
| Then, | x | - | x | = 2 |
| 10 | 15 |
3x - 2x = 60
x = 60 km.
| Time taken to travel 60 km at 10 km/hr = |  |
60 |  hrs |
= 6 hrs. |
| 10 |
So, Robert started 6 hours before 2 P.M. i.e., at 8 A.M.
 Required speed = |
|
60 | kmph. |
= 12 kmph. |
| 5 |
Discussion:
93 comments Page 5 of 10.
Abhi said:
6 years ago
How 60/5 comes, does any one please tell me?
Ishwar said:
5 years ago
Let calculate distance firs say d.
D/10-d/15=2 (he reach 12noon 2hr early).
By calculating we get d = 60km.
Let's speed is S to calculate S difference between travel at first speed rate and S rate is.
60/10-60/S=1 (because he reaches by 1 am, 1hr early).
By calculating this we get.
5S=60.
S = 12kmph.
D/10-d/15=2 (he reach 12noon 2hr early).
By calculating we get d = 60km.
Let's speed is S to calculate S difference between travel at first speed rate and S rate is.
60/10-60/S=1 (because he reaches by 1 am, 1hr early).
By calculating this we get.
5S=60.
S = 12kmph.
Ram sai said:
6 years ago
Thanks for the answer @Ashish.
Noorandeous said:
6 years ago
6 hours before 2 PM was not given how you added it?
Erigela vani said:
6 years ago
@Shivasai.
I think here the difference between the two times I. E12noon and 2pm is 2, and also time =d÷s, so we should take distance as "X" and speeds which they are given so x÷10-x÷15=2.
I think here the difference between the two times I. E12noon and 2pm is 2, and also time =d÷s, so we should take distance as "X" and speeds which they are given so x÷10-x÷15=2.
Vani said:
6 years ago
@Bhushan suriya.
How 5 hours will get at the last at 1:00pm?
How 5 hours will get at the last at 1:00pm?
Jethalal said:
5 years ago
@Vani.
If you want to reach at 1 P. M. Then from 8 o'clock to 1 the time comes out to be 5 hrs so we have taken 5hrs and from that we got speed.
If you want to reach at 1 P. M. Then from 8 o'clock to 1 the time comes out to be 5 hrs so we have taken 5hrs and from that we got speed.
Sania prathi said:
5 years ago
Thank you @Neha.
Mano said:
1 decade ago
I agree to vishu comment. How that step came ?
Divya said:
1 decade ago
Lets try a hit and trial method :
By increasing his speed by 5 km/hr (15-10) , he is saving 2 hours (2pm-12pm) , so when he reaches at 1 pm he increased speed by 2.5 (half of 5) = 12.5, from the options 12 is closest so that must be the answer :).
By increasing his speed by 5 km/hr (15-10) , he is saving 2 hours (2pm-12pm) , so when he reaches at 1 pm he increased speed by 2.5 (half of 5) = 12.5, from the options 12 is closest so that must be the answer :).
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