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 12 of 35.
K. srinivasan said:
1 decade ago
Let the speed of the car be 10km/h and so as the speed of the train is 50% more ie 50% of 10 is 5 and so the speed of the train can be assumed to be 15km/h. Based on this assumption also this problem can be solved.
Abraham said:
7 years ago
Speed of car be x.
Speed of train= x+x/2 = 3x/2 ie; 1.5x.
Train didnt run for 12.5min ie; 12.5/60 hrs.
Difference between time ran by both is 12.5/60hr.
ie: (75/x) - (75/1.5x) = 12.5/60.
Upon solving x= 120kmph.
Speed of train= x+x/2 = 3x/2 ie; 1.5x.
Train didnt run for 12.5min ie; 12.5/60 hrs.
Difference between time ran by both is 12.5/60hr.
ie: (75/x) - (75/1.5x) = 12.5/60.
Upon solving x= 120kmph.
Bindu sree said:
2 years ago
The speed of train and car = 150 : 100 = 3 : 2.
Speed = 1/time,
Time = 2 : 3.
Delay = 12.5 for train,
So, car time = train delay × 3 = 3 × 12.5 = 37.5min = 37.5/60 = 5/8h.
Finally speed = d/t =75/5/8 =120km/h.
Speed = 1/time,
Time = 2 : 3.
Delay = 12.5 for train,
So, car time = train delay × 3 = 3 × 12.5 = 37.5min = 37.5/60 = 5/8h.
Finally speed = d/t =75/5/8 =120km/h.
(127)
Yogi said:
4 years ago
@Yogi,
Train increase speed 1/2, means time decrease 1/3,
This 1/3 =12.5 minute. = 12.5/60 = 5/24 hour,
Speed = distance/time.
Speed(train)= 75km/5/24 = 360km/h,
Car speed = train speed/2,
Car speed =120kmph.
Train increase speed 1/2, means time decrease 1/3,
This 1/3 =12.5 minute. = 12.5/60 = 5/24 hour,
Speed = distance/time.
Speed(train)= 75km/5/24 = 360km/h,
Car speed = train speed/2,
Car speed =120kmph.
(1)
Insane said:
4 years ago
If you guys wonder how did 12.5 converts in 125/60*10 then;
As 12.5 min should be converted into hours.
So, 12.5/60 (to remove decimal from 12.5 bcos we cant divide),
We add * 10,
125/ 60*10 or 125/600.
As 12.5 min should be converted into hours.
So, 12.5/60 (to remove decimal from 12.5 bcos we cant divide),
We add * 10,
125/ 60*10 or 125/600.
Arvind Gupta said:
5 years ago
Late Train speed = X km/hrs.
Than Car speed will be = X+X/2 =3X/2 km/hrs,
Time_train - Time_car = Time - train stop.
75/X - 75/(3/2)X = 12.5/60,
75/X - 50/X = 25/120,
25/X = 25/120.
X = 120 km/hrs Ans.
Than Car speed will be = X+X/2 =3X/2 km/hrs,
Time_train - Time_car = Time - train stop.
75/X - 75/(3/2)X = 12.5/60,
75/X - 50/X = 25/120,
25/X = 25/120.
X = 120 km/hrs Ans.
(1)
Yogeshwar yaduwanshi said:
10 years ago
Suppose car speed : x.
Than 50% more speed train : 3x/2.
Than formula car is taken time : 75/x = T....(1).
And train is taken time : 75*2/3x = T-12.5/60....(2).
Both equation solve: x = 120 km/hr.
Than 50% more speed train : 3x/2.
Than formula car is taken time : 75/x = T....(1).
And train is taken time : 75*2/3x = T-12.5/60....(2).
Both equation solve: x = 120 km/hr.
Amit said:
1 decade ago
Sarvya Kanchna is right:-)
dont consider x with 100 consider with 50 like this.
=x+50x/100
=(100x+50x)/100
=150x/100
If you consider x with 100 then when we take LCM then eq.
=(100x^2+50)/100x
:-)
dont consider x with 100 consider with 50 like this.
=x+50x/100
=(100x+50x)/100
=150x/100
If you consider x with 100 then when we take LCM then eq.
=(100x^2+50)/100x
:-)
Preethi said:
1 decade ago
75/x - 75/(3/2)x is in KMPH and the term 12.5 mins is converted into secs. how could the answer can be given in KMPH by equating these two terms? please anyone who knows the explanation, explain me?
Vibha said:
1 decade ago
Since the Car covered the half distance while train was halting, the speed of car becomes 75/2 * 60/12.5 = 180KM/hr
Now Train is 50% faster than car so train's speed should be 180 + 90 = 270 KM/hr
Now Train is 50% faster than car so train's speed should be 180 + 90 = 270 KM/hr
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