2) A train 150 m long, is running at a speed o
long, is running at a speed of 90 km/h. Find the time taken by the ti
to cross a tree.
3) Find the distance covered by a car in 36 minutes moving at a uniform speed of
65 km/hr.
4) A train is running at a speed of 90 km/hr, crosses a pole in 10 seconds. Find the
length of the train.
5) A car travels 432 km on 48 litres of petrol. How far would it travel on 20 litres of
petrol?
6) If 36 men can do a piece of work in 25 days, in how many days will 15 men can
it?
Answers
2) solution see my 1st pic in attachment
3) Here ,
T = 65 km/h
S =0.6hour
D = ?
distance = s×t
= 65×0.6= 39 km
4) The train is moving at a speed of 60 km/hr. Let's assume ourselves to be stationary in the train. Thus we will see the pole to be moving backwards at a speed of 60 km/hr.
Now the question, actually, is stating that the time taken by the pole to cover the distance equivalent to that of the length of the train is 9 sec.
Given speed = 60 km/hr.
60 km/hr = (60*1000 m) ÷ (1*3600 s)
=16.666 m/s
So the pole travels 16.66 m in 1 sec. Thus the distance travelled by the pole in 9 sec (i.e., the length of the train) = 16.666*9
=149.994 m (almost 150 m)
5) 48 litres = 432 km
20 litres = x km
x= (20*432)/48 = 180 km
6) A person working for a day is normally known as a man day . So this work takes 36*25 = 900 man days to be finished. If the number of men get reduced, then the number of days must increase as the man days remain constant. Number of days required to finish the work = 900/15 = 60 days .
