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.?
8 kmph
11 kmph
12 kmph
14 kmph
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:
95 comments Page 8 of 10.

Das said:   2 decades ago
Hi, could u tell me why we have done 60/5 in last step ?

Xyz said:   2 decades ago
Its 2 hours
12 noon to 2pm = 2 hours

Nancy said:   1 decade ago
Yes, but why we are considering only 10 km/hr speed?

Why not 15 km/hr?

Arunkumar said:   2 decades ago
How to find that 2. We don't know the starting time. Then how that is calculated.

Naveen said:   10 years ago
Can anyone explain in easy way? It is hard to understand.

K.NAVEENA said:   10 years ago
2xy/(x + y) = [(2 * 10 * 15)/(10 + 15)] = 12kmph.

Marco said:   1 decade ago
The average speed :

2*10*15/10 + 15.
= 300/25.
= 12 km/h.

Kuru said:   1 decade ago
@Amir that was nice, and easy step to solve.

Thanks.

Bharat said:   1 decade ago
x/10-x/15=2. How did 60 comes?

Tarun said:   1 decade ago
Let the traveled distance X.

Then X/10-X/15 = 2.

X = 60 kmph.

Time taken to travel 60 km at 10 kmph is 6 hours.

So the Mr stylish Yankee Robert Peterson a billionaire person started 6 hours before 2 pm. i.e 8 pm.

Speed of Mr equals to 60/(8 pm-1 pm) = 12 kmph.


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