Aptitude - Time and Distance - Discussion

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.

Can anybody explain if both the vehicle reaches at the same time then where is the delay arises I am talking about if two vehicles reach at the same time then how this equation came?

(75/x) - (75/ (3/2) x) =12.5/60, 12.5 minutes delay will not be there if both the vehicles reach at the same time please help,

Let me explain, the time taken by car to reach B point is 40 min (just assume). Then the time taken by train is 27.5 min without stopping in stations. Hence 12.5 equal to the time taken by car (-) time taken by train without a stop in stations.

Hope you understand, thank you.

The Speed of train increase by 1/2, means time reduce by 1/3, this 1/3 time reduction is 12.5 minute.

So, 1/3 = 12.5/37.5.

Means the car will take three-time of 12.5 minutes which 37.5 minutes.
75 x 60/37.5 = 120kmph.

@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.

Let the car speed be x.

Speed of train = 150/100x = 3/2xkmph(explain 25*3/25*2).
75/x-75/3/2x = 12.5/60.
75/x-75/3/2x = 125/600.
75/x-75*2/3x = 5/24.
75/x-150/3x = 5/24.
75/x-50/x = 5/24.
25/x = 5/24.
x = 25*24/5.
x = 5*24.
x = 120.

The Answer method, I correct with 1 simple mistake in calculations.
75/x - 75/(3x/2) = 12.5 minutes.
Now, the equation is correct but Now since time is in Minutes we need to convert it into seconds.
We Know, 1min = 60seconds this means, 12.5min = (12.5X 60)seconds.

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.

I think the answer is 110.

Why was it taken 125/10 * 60?

Please explain.

The car and train reached 75km at the same time.the train was late for 12.5 mins.
The train could reach 12.5 mins faster than the car.
* 75/x is the timing of car to reach 75kms.
*75/(3x/2) +12.5/60(time for stops) is the time taken by train to reach 75kms.
*Both the timings are equal since the time taken by both car and train are equal so then you can get the equation.
75/x = 75/(3x/2) + 12.5/60.
75/x - 75/(3x/2) = 12.5/60.