Aptitude - Time and Distance - Discussion

Due to the stoppages it travelled 9km less. So
For 1 hr -> 54km.

t(hr) -> 9km.

t = 9/54 = 1/60 = 60/6 = 10min.

Why you have taken 54 and why not 45?

See..the bus runs up to 54 kmph in 60m. in nonstop mode.

If 45km in stop mode, the bus will take 72 minutes to travel 54 km in stop mode.(60/45*54).

So here bus taking 12 more minutes to reach at the destination but in 72 minutes. As per question, in 60 minutes the bus will take extra minutes to halt => 12/72*60=10 proved. Answer is 10.

For those who got i2 min as answer.

Solve like this;

As distance is same....

54=d/(1-x).........(1) where x is the stoppage time.

45=d/1.............(2).

Solving eq 1 & 2,we get x=0.166 hrs. So in minutes ANS = 10.

Excluding stoppages, the speed of a bus is 54 kmph.
Including stoppages, the speed of a bus is 45 kmph.

The difference between 54 and 45 is 9 that means the bus stopped.
Overall about 9 kms.

Formula : (Difference/Bigger value)*60.

Therefore (9/54)*60.

If speed is 54 kmph.

So in one hour bus travels 54 km.

Again time taken by bus to travel 54 km with speed 45 kmph will be (54/45) *60 min=72 min.

So to reach at the same position more time required 12 min.

So 12 min is the stopped time.

Why we are considering 54 kmph rather 45 kmph?

To all those who have doubt why 54 kmph is considered. The problem is to find how many minutes does the bus stops in stoppages.

54 kmph means it travels 54 km per a single hour (i.e 60 min) excluding stoppages.

Including stoppages speed reduced to 45 km per a single hour. It means per one hour due to stoppages there is 9 km loss per a single hour.

We should take 54 kmph because we should know what time it takes for bus for a km. So 54 km-->60 min then 1 km-->60/54 min.

For 9 km--> (9*60) /54 = 10 min.

Why we are considering 54 kmph rather 45 kmph?

Please explain in min to sec and min to hours.