Aptitude - Time and Distance - Discussion
Discussion Forum : Time and Distance - General Questions (Q.No. 11)
11.
In covering a distance of 30 km, Abhay takes 2 hours more than Sameer. If Abhay doubles his speed, then he would take 1 hour less than Sameer. Abhay's speed is:
Answer: Option
Explanation:
Let Abhay's speed be x km/hr.
| Then, | 30 | - | 30 | = 3 |
| x | 2x |
6x = 30
x = 5 km/hr.
Discussion:
209 comments Page 11 of 21.
Teja said:
9 years ago
Total = 30 km.
Speed = 1 : 2.
That is time = 2 : 1.
Difference between time is 1 = 3(3 get from question is more than 2 hrs and less than 1 hrs)
2 * 3 = 6;
Abhay speed =30/6 = 5 km/hrs.
Sameer speed = 30/4 = 7.5 km/hrs.
Speed = 1 : 2.
That is time = 2 : 1.
Difference between time is 1 = 3(3 get from question is more than 2 hrs and less than 1 hrs)
2 * 3 = 6;
Abhay speed =30/6 = 5 km/hrs.
Sameer speed = 30/4 = 7.5 km/hrs.
Mk islam said:
9 years ago
Let total time Sameer = x hours.
Total time Abhay = x + 2 hours.
Speed Sameer = 30/x kmh.
Speed Abhay = 30/(x + 2) kmh.
If speed a two times = 2(30/x + 2) kmh.
So, 2(30/x + 2) km = 1 hour.
1. km=1/2(30 x+2),
30. km=30/2(30/x+2).
According to question,
x - 30/ 2(30/x + 2) = 1,
x = 4 h.
Speed Abhay = 30/x + 2 kmh,
= 30/4 + 2 = 5 kmh.
Total time Abhay = x + 2 hours.
Speed Sameer = 30/x kmh.
Speed Abhay = 30/(x + 2) kmh.
If speed a two times = 2(30/x + 2) kmh.
So, 2(30/x + 2) km = 1 hour.
1. km=1/2(30 x+2),
30. km=30/2(30/x+2).
According to question,
x - 30/ 2(30/x + 2) = 1,
x = 4 h.
Speed Abhay = 30/x + 2 kmh,
= 30/4 + 2 = 5 kmh.
Manish Pillai said:
9 years ago
Only consider Abhay the ratio of his speeds is 1 : 2.
So, the ratio of time he would take would be 2 : 1.
2x for 1 case and x for 2.
Given 2x - x = 3
so, x = 3hrs.
So, for 1 case he will take 6 hrs to complete the journey.
His speed will be 30/6 = 5km/hr.
So, the ratio of time he would take would be 2 : 1.
2x for 1 case and x for 2.
Given 2x - x = 3
so, x = 3hrs.
So, for 1 case he will take 6 hrs to complete the journey.
His speed will be 30/6 = 5km/hr.
Rithesh said:
9 years ago
Thanks @Devi.
Rithesh said:
9 years ago
Thanks @Devi.
Asha said:
9 years ago
Thank you for the great explanation @Devi.
Barsha said:
9 years ago
Thank you @Kingstan.
Shivakar said:
9 years ago
Let Sameer speed is X km/h and time taken by Sameer is T.
Let Abhay speed is Y km/h.
Then, According to question.
30/X = T........(i)
30/Y = T+2....(ii)
Now,
Abhay speed is Double means 2Y
so, time taken by Abhay
30/2Y=T-1.....(iii)
Substitute the Eqn..(iii) in Eqn...(ii).
30/x-30/2Y = T+2-(T-1),
30/X-30/2Y = T+2-T+1,
(60-30)/2Y = 2+1,
30/2Y = 3,
30 = 6Y,
Hence,
Y = 5 kmph.
Let Abhay speed is Y km/h.
Then, According to question.
30/X = T........(i)
30/Y = T+2....(ii)
Now,
Abhay speed is Double means 2Y
so, time taken by Abhay
30/2Y=T-1.....(iii)
Substitute the Eqn..(iii) in Eqn...(ii).
30/x-30/2Y = T+2-(T-1),
30/X-30/2Y = T+2-T+1,
(60-30)/2Y = 2+1,
30/2Y = 3,
30 = 6Y,
Hence,
Y = 5 kmph.
Vikas said:
9 years ago
We have to find the speed of Abhay.
So,
let speed of Abhay = x km/hr.
Time taken by Sameer = t hrs.
Now, first condition,
Speed = distance/time.
So, Abhay takes 2 hrs more than Sameer that comes.
(30/t+2)= x ----> eq(1).
Now condition second,
If abhay doubles his speed that is x km/hrs to 2xkm/hr. Time t reduces to t-1,
{30/(t+2)}=2x ----> eq(2).
By solving equation1 and 2.
x = 5km/hr.
So,
let speed of Abhay = x km/hr.
Time taken by Sameer = t hrs.
Now, first condition,
Speed = distance/time.
So, Abhay takes 2 hrs more than Sameer that comes.
(30/t+2)= x ----> eq(1).
Now condition second,
If abhay doubles his speed that is x km/hrs to 2xkm/hr. Time t reduces to t-1,
{30/(t+2)}=2x ----> eq(2).
By solving equation1 and 2.
x = 5km/hr.
Haeshal said:
8 years ago
I don't understand it. Please, someone explain it.
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