Question

If it has rained $276mm$ in the last $3$ days, how many centimeters of rain will fall in one full week ($7$ days)? Assume that the rain continues to fall at the same rate.

Answer 1

Calculate the required value using unitary method

It is given that,

Amount of rain in $3$ days $=276mm$

$\Rightarrow$ Amount of rain in $1$ day $=\frac{276}{3}mm$ [by unitary method]

Amount of rain in $1$ day $=92mm$

$\Rightarrow$ Amount of rain in $7$ days $=92\times 7mm$

Amount of rain in $7$ days $=644mm$

$\Rightarrow$Amount of rain in $1$ week $=644mm$ $\left[\because 1\mathrm{week}=7\mathrm{days}\right]$

$\Rightarrow$Amount of rain in $1$ week $=\frac{644}{10}cm$ $\left[\because 1mm=\frac{1}{10}cm\right]$

$\Rightarrow$Amount of rain in $1$ week $=64.4cm$

Hence, $64.4cm$ of rain will fall in one full week ($7$ days).