Aptitude - Time and Distance - Discussion

@Yash Soni.

If we take 45 then the bus is already stopped. And 45 is not the actual bus speed. It's the speed that is just calculated when the bus is stopped at stops. So 54 is its actual speed. So we should take 54.

I'm not clear why we take 54. I think we take 45 because in 54 the bus is not stopped then how can 54 gives us the stoppage time?

If we take 45 so we get the answer (12).

@ALL.

The direct formula is (excluding-including*60/excluding).

Ans is 12 min. Solve the problem by taking 10mins and then 12mins.

@All.

if ans 10mins, 54*60 = 45*(60+10) which is not correct
if ans 12 mins, 54*60 = 45*(60+12) which is correct
So ans is 12 mins, not 10 mins.

Can anyone clearly explain why we had taken 9/54 instead of 9/45?

Consider A and B two bus,

A with stoppages km/hr - 45
B without stoppage km/hr - 54

1 hour travel.
B far away from A.
that distance is 9 km.

Just think 9 km A don't stop in anywhere there speed is increased. Because A's is the Avg speed 45 km/hr.

Here we can't find the stoppage from A's speed
Go next option B,
from B the bus,
Easy to find out the time taken from 9 min travel that 9 min travel is A's stoppage time

So,
distance = time * speed,
54 km = 1 hour * 54 km/hrs,
if 1 km = time ? * 54km/hrs,
9 = t* 54,
1/6 = t (in hours),

In min,
1/6*60 =10min,

Due to stoppages, the bus lags =(54-45)Kmph=9Kmph in speed.
So, time taken at each stoppages= Speed /original speed.
=9/54 hrs,
=9*60/54mins,
=540/54mins,
=10mins.

There is another easier method.

54 km is traveled in 1 hr
1 km------------- 1/54 hr
45 km---------- 1/54*45= 5/6 hrs.

Now, if we subtract the times, i.e 1 - 5/6 = 1/6 hr (we are subtracting this because 45 km should have been traveled in 5/6 hrs and not 1 hr. Hence, the time taken is more so subtracting, we get the no. of minutes the bus stopped).

converting to minutes 1/6 * 60 = 10 min.

The distance between A and B is 999km.The express train travels place A at 6 a.m. and runs at the speed of 55.5 kmph. The train stops on the way for 1 hour 20 minute.The train reaches B at?

Please solve this question.