Question

Two taps X and Y can fill a tank in 9 hours and 6 hours respectively. If both of them are opened
together, how long will they take to fill the tank completely?​

Answer 1

${\huge{\underline{\underline{\pink{\sf{Answer}}}}}}$

• There are two taps - A & B
• A can fill the tank in 9 hours
• B can fill the tank in 6 hours

So ,

${\longrightarrow} \: \bf{one \: hour \: work \: of \: a} = \frac{1}{9}$

$\longrightarrow \bf{one \: hour \: work \: of \: b = \frac{1}{6} }$

So, if both are on simultaneously ..

$\longrightarrow \bf{one \: hour \: work \: of \: both} = \frac{1}{9} + \frac{1}{6} \\ \implies \frac{2 + 3}{18} \implies \frac{5}{18}$

$\bf{so \: they \: can \: fill \: the \: tank \: in} = \frac{18}{5} hours$

$\bf{or}$

$\pink \star \: \bf{3.6hours}$