Monicaa Abhijit Solutions for Chapter: Direct and Inverse Variation, Exercise 7: EXEMPLAR PROBLEMS

Assuming land to be unifromely fertile, the area of land and the yield on it vary:

If $12$ pumps can empty a reservoir in $20$ hours, then time required by $45$ such pumps to empty the same reservoir is _____ hours.

If the area occupied by $15$ postal stamps is $60 {\mathrm{cm}}^2$ , then the area occupied by $120$ such postal stamps will be _____${\mathrm{cm}}^2$.

If $\mathrm{p}$ and $\mathrm{q}$ are in inverse proportion then $(\mathrm{p}+2)$ and $(\mathrm{q}-2)$ are also in inverse proportion.

The mass of an aluminium rod varies directly with its length. If a $16 \mathrm{cm}$ long rod has mass of $192 \mathrm{g}$, find the length of the rod whose mass is $105 \mathrm{g}$.

At a particular time, the length of the shadow of Qutub Minar whose height is $72 \mathrm{m}$ is $80 \mathrm{m}$. What will be the height of an electric pole, the length of whose shadow at the same time is $1,000 \mathrm{cm}$?

A bowler throws a cricket ball at a speed of $120 \mathrm{km}/\mathrm{h}$. How long does this ball take to travel a distance of $20 \mathrm{m}$ to reach the batsman?

There are $20 \mathrm{g}$ of protein in $75 \mathrm{g}$ of sauted fish, How many grams of protein is in $225 \mathrm{g}$ of that fish?