Asit Das Gupta and Alok Kumar Solutions for Exercise 3: EXERCISE 3

A school bus travelling at a speed of $48 \mathrm{km}/\mathrm{h}$ reaches from a stop to the school in $45$ minutes. What is the distance of the school from the stop?

The speed of a car $45 \mathrm{km}/\mathrm{h}$. Find its speed in $\mathrm{m}/\mathrm{s}$. 

A train runs at $72\mathrm{km}/\mathrm{hr}$. What is its speed in $\mathrm{m}/\min$. 

A train takes $3$ hours to reach station $\mathrm{B}$ from station $\mathrm{A}$. Which is $144 \mathrm{km}$ away. How long it will take to cover $240 \mathrm{km}$?

The distance between two places is $120 \mathrm{km}$. A car travelling at a certain speed can cover the distance in $2 \mathrm{hours} 30 \mathrm{minutes}$. By how many $\mathrm{km}/\mathrm{h}$  should the speed of the car be increased for it, to take $30 \mathrm{minutes}$ less to cover the distance?

Two cars start from the same place at the same time in the same direction. The speed of the first car is $70 \mathrm{km}/\mathrm{hr}$ and that of the second car is $20 \mathrm{m}/\mathrm{s}$. What is the distance between the cars after $1 \mathrm{hour} 15 \mathrm{minutes}$?

A train takes $6 \mathrm{hours}$ to complete a journey at a speed of $72 \mathrm{km}/\mathrm{hr}$. How long will another train take to complete the journey, if its speed is $15 \mathrm{m}/\mathrm{s}$?

Ramesh could run a $100 \mathrm{m}$ race in $20$ seconds. After training, he can finish the race in $15$ seconds. By how much has he improved his speed.