Question

The length and breadth of a playground are $80m$ and $35m$ respectively.
(i) Find the cost of levelling it at $Rs.4.50$ per square meter.
(ii) How long will a boy take to go three times round the field, if he walks at rate of $1.5m$ per second?

Answer 1

Area of playground $=$ \length $\times$ breath $=80\times 35=280m^2$

$\Rightarrow$ Total cost $=Rs.2800\times 45=Rs.12600$

Perimeter of playground $=2(length+breath)=2(80+35)$

$=\left(2\right(115)=230m$

$\Rightarrow times=\frac{distance}{speed}=\frac{230}{1.5}=153.33sec$.