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 4 of 21.
Abdul Majid P said:
1 decade ago
Hi friends,
Consider Abhayz speed be x km/hr, and time taken to cover 30km for Sameer is t;
We know, in both the cases, distance are equal.Therefore we can use this equation: v= d/t => d = v*t;
x(t+2) = 2x(t-1),
From the above we get t = 4, time for Sameer, but Abhay is 2hr more
in first case, So t+2 = 4+2 = 6hr.
Therefore x = d/t = 30/6 = 5kmph.
Consider Abhayz speed be x km/hr, and time taken to cover 30km for Sameer is t;
We know, in both the cases, distance are equal.Therefore we can use this equation: v= d/t => d = v*t;
x(t+2) = 2x(t-1),
From the above we get t = 4, time for Sameer, but Abhay is 2hr more
in first case, So t+2 = 4+2 = 6hr.
Therefore x = d/t = 30/6 = 5kmph.
Vignesh sk said:
8 years ago
Distance=30km/h0r.
time taken by Sameer is t,
Abhay travelling with a Speed X.
Case 1:
time taken by Abhay to cover 30km is 30/X = t+2.
Case 2(doubles speed):
time taken by Abhay to cover 30km is 30/2X = t-1.
(30/X)- (30/2X) = (t+2)-(t-1),
(30/X) - (30/2X) = t+2-t+1,
(30*2X) - (30*X) = 3 (2X^2) //LCM,
60X - 30X = 6 X^2,
30X = 6 X^2,
30 = 6 X,
X = 5.
time taken by Sameer is t,
Abhay travelling with a Speed X.
Case 1:
time taken by Abhay to cover 30km is 30/X = t+2.
Case 2(doubles speed):
time taken by Abhay to cover 30km is 30/2X = t-1.
(30/X)- (30/2X) = (t+2)-(t-1),
(30/X) - (30/2X) = t+2-t+1,
(30*2X) - (30*X) = 3 (2X^2) //LCM,
60X - 30X = 6 X^2,
30X = 6 X^2,
30 = 6 X,
X = 5.
Urvesh Radadiya said:
2 years ago
@All.
My explanation is very simple;
T = D/S.
Suppose the speed of Abhay is x.
First case:
It takes 2 hours more than Samir.
T + 2 = 30/x ---> (1)
Second case:
when speed is double then 2x
it takes 1 hour less so
T-1=30/2x ----> (2)
Compare eq 1 &2;
30/x-2=T.
30/2x+1=T.
30/x-30/2x = 3.
Solving the above eq we get x=5km/h=> Abhay's speed.
My explanation is very simple;
T = D/S.
Suppose the speed of Abhay is x.
First case:
It takes 2 hours more than Samir.
T + 2 = 30/x ---> (1)
Second case:
when speed is double then 2x
it takes 1 hour less so
T-1=30/2x ----> (2)
Compare eq 1 &2;
30/x-2=T.
30/2x+1=T.
30/x-30/2x = 3.
Solving the above eq we get x=5km/h=> Abhay's speed.
(242)
Shivam said:
4 years ago
This is how I understand the problem.
Let Abhay's speed be 'x' kmph.
Let time taken by sameer be 't' hr.
Distance = 30km.
According to first condition,
Sameer time (t) = 30/x - 2 hr.
According to second condition,
Sameer time (t) = 30/2x + 1 hr.
Therefore,
30/x - 2 = 30/2x + 1.
After soving this,
X = 5kmph.
Therefore Abhay's speed is 5kmph.
Let Abhay's speed be 'x' kmph.
Let time taken by sameer be 't' hr.
Distance = 30km.
According to first condition,
Sameer time (t) = 30/x - 2 hr.
According to second condition,
Sameer time (t) = 30/2x + 1 hr.
Therefore,
30/x - 2 = 30/2x + 1.
After soving this,
X = 5kmph.
Therefore Abhay's speed is 5kmph.
(5)
Rahul said:
1 decade ago
Let Abhay's speed be x km/hr
and sameer's speed be y km/hr
Abhay takes 2 hours more than Sameer
i.e (30/x)-(30/y)=2 ........ I
Abhay doubles his speed, i.e his speed becomes 2x
then he would take 1 hour less than Sameer
i.e (30/y)-(30/2x)=1......... II
ADD I and II
you will get
(30/x)-(30/2x)=3.......... III
solve III you will get x=5 km/h
and sameer's speed be y km/hr
Abhay takes 2 hours more than Sameer
i.e (30/x)-(30/y)=2 ........ I
Abhay doubles his speed, i.e his speed becomes 2x
then he would take 1 hour less than Sameer
i.e (30/y)-(30/2x)=1......... II
ADD I and II
you will get
(30/x)-(30/2x)=3.......... III
solve III you will get x=5 km/h
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.
Sanjay parashar said:
10 years ago
Guys please solve this question by answer don't get confused.
Example: 1st option is 5 km/hr if we take then Abhaya speed 30/5 = 6 hr then Sameer has time 4 hr means Abay has 2 hr more then Sameer after then speed double means 10 km/hr, Abhay takes time 30/10 = 3 hr mean 1 hr less then Sameer. So 1st option is correct answer.
Example: 1st option is 5 km/hr if we take then Abhaya speed 30/5 = 6 hr then Sameer has time 4 hr means Abay has 2 hr more then Sameer after then speed double means 10 km/hr, Abhay takes time 30/10 = 3 hr mean 1 hr less then Sameer. So 1st option is correct answer.
Akshay said:
2 years ago
We know that,
1st case ---> (1)
If Sameer takes 2 hours,
Then, Abhay takes 4 hours.
So,
Sameer takes 2 * 60 = 120 seconds.
&Abhay takes 4 * 60 = 240 seconds.
2nd case ----> (2)
Abhay takes 1hour less than Sameer,
So,
2-1 = 1 * 60 = 60seconds
So,
Abhay's speed is
Case(1)&(2)
240 + 60 = 300Seconds;
Then 300/ 60 = 5.
1st case ---> (1)
If Sameer takes 2 hours,
Then, Abhay takes 4 hours.
So,
Sameer takes 2 * 60 = 120 seconds.
&Abhay takes 4 * 60 = 240 seconds.
2nd case ----> (2)
Abhay takes 1hour less than Sameer,
So,
2-1 = 1 * 60 = 60seconds
So,
Abhay's speed is
Case(1)&(2)
240 + 60 = 300Seconds;
Then 300/ 60 = 5.
(19)
Maaz said:
1 decade ago
Don't make it so complicated.
Suppose speed of Abhay is x kmph.
Time taken by sameer is t hr.
From the given statement we will get 2 equation.
30/x = t +2.
30/2x = t -1.
Here we got 2 equations And to unknown Variables. X&t.
Therefore after solving above 2 equations. We'll get the answer which is x=5 kmph.
Thanks.
Suppose speed of Abhay is x kmph.
Time taken by sameer is t hr.
From the given statement we will get 2 equation.
30/x = t +2.
30/2x = t -1.
Here we got 2 equations And to unknown Variables. X&t.
Therefore after solving above 2 equations. We'll get the answer which is x=5 kmph.
Thanks.
Sumit said:
1 decade ago
Let, abhay takes X km/hr to cover 30km.
Sameer takes Y km/h to cover 30km.
So first case,
(30/X)-(30/Y) = 2;[time taken by abhay - time taken by sammer = 2hr]
Now,
Abhay doubles his speed
(30/Y)-(30/2X) = 1;
[time taken by sammer - time taken by abhay after doubling the speed = 1 ]
Solving both equation
x=5km/hr.
Sameer takes Y km/h to cover 30km.
So first case,
(30/X)-(30/Y) = 2;[time taken by abhay - time taken by sammer = 2hr]
Now,
Abhay doubles his speed
(30/Y)-(30/2X) = 1;
[time taken by sammer - time taken by abhay after doubling the speed = 1 ]
Solving both equation
x=5km/hr.
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