Aptitude - Time and Distance - Discussion
Discussion Forum : Time and Distance - General Questions (Q.No. 4)
4.
A train can travel 50% faster than a car. Both start from point A at the same time and reach point B 75 kms away from A at the same time. On the way, however, the train lost about 12.5 minutes while stopping at the stations. The speed of the car is:
Answer: Option
Explanation:
Let speed of the car be x kmph.
| Then, speed of the train = | 150 | x | = |  |
3 | x |  kmph. |
| 100 | 2 |
 |
75 | - | 75 | = | 125 |
| x | (3/2)x | 10 x 60 |
 |
75 | - | 50 | = | 5 |
| x | x | 24 |
| x = |
|
25 x24 | |
= 120 kmph. |
| 5 |
Discussion:
350 comments Page 4 of 35.
Kishorebabu said:
1 year ago
Convert km/h to m/s.
S(c) = 75000/T -->(1)
S(tr) = 75000/(T-12.5x60)-->(2)
S(tr) = 3/2S(c) -->(3)
Sub (3) in (2).
3/2s(c) = 75000/(T-12.5x60).
sub (1) in above;
(3/2).(75000/T) = 75000/(T-12.5x60).
T = 3x12.5x60 ---->(4)
Sub (4 in (1) [to get the speed of the car].
S(c) = (75000/3x12.5x60 ).(18/5).
s(c) = 120km/h.
S(c) = 75000/T -->(1)
S(tr) = 75000/(T-12.5x60)-->(2)
S(tr) = 3/2S(c) -->(3)
Sub (3) in (2).
3/2s(c) = 75000/(T-12.5x60).
sub (1) in above;
(3/2).(75000/T) = 75000/(T-12.5x60).
T = 3x12.5x60 ---->(4)
Sub (4 in (1) [to get the speed of the car].
S(c) = (75000/3x12.5x60 ).(18/5).
s(c) = 120km/h.
(16)
Sai Durga said:
3 years ago
Let the speed of the train be x.
So, train speed 50% faster than car means x + x/2 = 3x/2, speed = 75km/hr,
Time delayed = 12.5 mins = 12.5/60 sec.
Now;
D/s = T; (here speed = speed of the car -speed of the train),
So,
75/x -75/3x/2 = 12.5/60.
75/x - 50/x = 5/24.
x = 25 x 24/5.
x = 120 km/hr.
So, train speed 50% faster than car means x + x/2 = 3x/2, speed = 75km/hr,
Time delayed = 12.5 mins = 12.5/60 sec.
Now;
D/s = T; (here speed = speed of the car -speed of the train),
So,
75/x -75/3x/2 = 12.5/60.
75/x - 50/x = 5/24.
x = 25 x 24/5.
x = 120 km/hr.
(13)
Saloni Adhikari said:
3 years ago
Here, How can we say given time in the question is equal to the value obtained after subtraction? Please explain me.
(13)
Renny said:
10 months ago
Thanks for explaining the answer @VIJETH BK.
(11)
Piyush said:
4 years ago
@All.
So many of us are confused in where the hell this (150x/100) came from right.
So, my simple explanation is that see the train is 50% faster than car.
Now, consider car speed is X so the train speed will be (X+ 50% of X) Now calculate the train speed.
And you will get (X + 50X/100) = 150X/100.
Hope this helps.
So many of us are confused in where the hell this (150x/100) came from right.
So, my simple explanation is that see the train is 50% faster than car.
Now, consider car speed is X so the train speed will be (X+ 50% of X) Now calculate the train speed.
And you will get (X + 50X/100) = 150X/100.
Hope this helps.
(9)
Abhishek S k said:
4 months ago
I didn't understand this, anyone please explain to me?
(9)
Anu said:
3 months ago
Most of people saying 1/2 instead of 3/2 is wrong.
The train is 50% more means 1/2 and also 1 for the car speed is added, So it's 3/2.
The train is 50% more means 1/2 and also 1 for the car speed is added, So it's 3/2.
(9)
Rohan said:
3 years ago
Someone help me in this by explaining this.
(8)
Jackie said:
1 year ago
Can anyone explain to me, how 12.5/60 9is = 5/24?
(7)
Jithen M S said:
4 months ago
(The train can travel 50% faster than a car).
This means the train is travelling 1/2 time faster than the car, not 3/2 time faster.
Final Answer: Speed of the car = 100 kmph.
This means the train is travelling 1/2 time faster than the car, not 3/2 time faster.
Final Answer: Speed of the car = 100 kmph.
(7)
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