In a slow sand filter, water is supplied at the rate of $24$

million litres per day and rate of filtration is $5\frac{m^3}{h}\frac{?}{m^2}.$ If

backwashing is done for $15$ minutes at the rate of $5$ times of

rate of filtration for every $24$ hours $($Let $L$:$B=2$:$1),$ then:

Find the volume of water filtered between backwashing

in $m^3.$

$($A$)23,750m^3$

$($B$)24,000m^3$

$($C$)24,860m^3$

$($D$)25,390m^3$

Find the volume of water used in backwashing in $m^3.$

$($A$)250m^3$

$($B$)500m^3$

$($C$)750m^3$

$($D$)1250m^3$