Prakash Tiwari and Ishita Joshi Solutions for Chapter: Comparing Quantities, Exercise 12: Let's Practice

Express the following speeds in terms of $\mathrm{m}/\sec$.

$63\mathrm{kmph}$

Express the following speeds in terms of $\mathrm{km}/\mathrm{hr}$.

$210 m/\sec$

Express the following speeds in terms of $\mathrm{km}/\mathrm{hr}$

$72 m/\sec$

A train travels with a constant speed of$72 \mathrm{kmph}$. How long will it take to cover $120\mathrm{km}$ $?$

How much time does it take for a bird to flying at a speed of $42\mathrm{kmph}$ to travel a distance of $2100$kilometres.

John rides to his village from his home at a speed of $60 \mathrm{kmph}$ and while coming back he rides at a speed of $45 \mathrm{kmph}$. If his total travelling time was $3.5 \mathrm{hrs}$, what was the total distance he travelled in the trips.

Meera drove her car at a certain speed for first $4\mathrm{hrs}$ and increased his speed by $8\mathrm{kmph}$, for the next $5\mathrm{hrs}$.If the total distance travelled by her was $400\mathrm{km}$, then find the speed at which at which meera drove her car at different times.

Bhargav travelled by bus at a speed of $40\mathrm{kmph}$. He then boarded a train which moved at the speed of $60\mathrm{kmph}$ and reached his destination.If the entire distance covered was $150\mathrm{km}$ in a duration of $3\mathrm{hrs}$, then how much distance he travelled by train.