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:
345 comments Page 24 of 35.
Harika said:
8 years ago
I understood. Good explanation @Dhinesh.
JIGNESH said:
8 years ago
How can 125/ (10 x 60) came? Please Explain me.
Rahul said:
8 years ago
Let Car speed = x kmph.
Train's speed is 50% more than car.
So, train's speed = x + 50x/100.
= 150x / 100.
= 3x/2.
Train's speed is 50% more than car.
So, train's speed = x + 50x/100.
= 150x / 100.
= 3x/2.
Rahul said:
8 years ago
@Jignesh.
Time is given in minutes. So to change it in hours, it is divided by 60.
And 10 has been placed for the decimal point.
Time is given in minutes. So to change it in hours, it is divided by 60.
And 10 has been placed for the decimal point.
Madhu said:
8 years ago
@Bdboy Hasan.
How do you say car's speed is 3x?
How do you say car's speed is 3x?
Nng said:
8 years ago
Hi, can you please explain why we are subtracting the time of car and train to get 12.5 minutes?
Sanju said:
8 years ago
Good explanation, thanks @Raihan.
Chirag Painter said:
8 years ago
Let speed ratio=car:train=100:150=2:3.
Here distance is same so as per the rule "if distance is same then speed ratio is inversely proportional to time"
Speed ratio = 2:3
Time ratio = 3:2
Therefore car usual time = 3 * 12.5 = 37.5 min.
And train usual time = 2 * 12.5 = 25 min.
Now, speed of car = Distance/time,
= 75kmph / 37.5 min,
= 2.
Now convert into hour=2 * 60 = 120kmphr.
Here distance is same so as per the rule "if distance is same then speed ratio is inversely proportional to time"
Speed ratio = 2:3
Time ratio = 3:2
Therefore car usual time = 3 * 12.5 = 37.5 min.
And train usual time = 2 * 12.5 = 25 min.
Now, speed of car = Distance/time,
= 75kmph / 37.5 min,
= 2.
Now convert into hour=2 * 60 = 120kmphr.
Suvasish Singha said:
8 years ago
Let, Speed of the train be X kmph.
Than, Speed of the train= x + (x * 50/100).
= x + x/2,
= (2x+x) / 2,
= 3x/2.
Than, Speed of the train= x + (x * 50/100).
= x + x/2,
= (2x+x) / 2,
= 3x/2.
Ravikumar J said:
8 years ago
Good explanation, thank you @Rihan.
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