Question

A water bottle contains $4\frac{4}{5}litres$ water. Rohit drinks $1\frac{3}{5}litres$ water every hour. Does he has enough water to last for $4hours?$

Answer 1

Finding amount of water Rohit drinks in $4hours$

Given that,

Amount of water in a water bottle $=4\frac{4}{5}litres=\frac{5\times 4+4}{5}litres=\frac{24}{5}litres$

Amount of water Rohit drinks every hour $=1\frac{3}{5}litres=\frac{5\times 1+3}{5}litres=\frac{8}{5}litres$

So, the amount of water drank by Rohit in $4hrs=4\times$Amount of water Rohit drinks in one hour

$$\begin{gathered} =4\times \frac{8}{5} \\ =\frac{32}{5}litres \end{gathered}$$

$\because \frac{32}{5}>\frac{24}{5}$

Thus, the amount of water drank by Rohit in $4hrs$more than the amount of water in the bottle

Hence, Rohit does not have enough water to last for $4hrs$.