Ramu walks at 3kms per hour while his brother Somu walks at 4kms per hour. They both started to school, which is 2kms away from their house at 7:00 A.M. Then, which of these is are correct?
Somu reaches school at 7:20 AM
Somu reaches school 10 mins earlier than Ramu
Ramu reaches school at 7:30 AM
All the above
Ramu =3 kmph Somu =4 kmph Both starts at 7 AM Distance =2km
Time taken by Ramu ⇒S=v×t
2=3×t
t=23hr=23×60
=40min
Time taken by Somu ⇒2=4×t
t=12hr=30 min.
∴ Somu reaches school 10 mins earlier than Ramu.
A goods train of length 500 m transverse a 2-km-long tunnel at a constant speed of 36 km/hour. The time needed for the train to completely pass through the tunnel is
3 minutes 20 seconds
4 minutes 10 seconds
4 minutes 40 seconds
6 minutes 10 seconds
The time taken by a person to cover 150 km was 2.5 hrs more than the time taken in the return journey. If he returned at a speed of 10km/hr more than the speed of going, what was the speed per hour in each direction?
going speed =−30km/hr, returning=−20km/hr
going speed =20km/hr, returning=30km/hr
going speed =30km/hr, returning=40km/hr
going speed =30km/hr, returning=20km/hr
The present ages of Reena and Usha ar 24 and 36 yr respectively. What was the ratio between the ages of Usha and Reena respectively 8 yr ago?
7:4
4:7
11:8
8:11
Age of Reena after 8yr=24−8=16yr Age of Usha After 8yr=36−8=28 So, the ratio will be 1628=47
A train is running at a uniform speed of 60km/h. How much time it will take to cover a distance of 300km?
5 h
4.5 h
6 h
7 h
$$speed=\frac{distance}{time}$$ $$time=\frac{distance}{speed}$$ $$time=\frac{300}{60}h$$ $$time=5 hr$$
If a man walks 17 km in 5 hours, how long(in hrs) would he take to walk 20.4 km
6
5
8
None of these
Time taken to walk 17km=5hrs. Time taken to walk $1km=\dfrac{5}{17}hrs.$ Time taken to walk $20.4km=\dfrac{5}{17} \times20.4$
$=6 hrs.$