Pipes A and B can fill a tank in 12 mns and 15 mns If both are opened together ,how - Maths - Direct and Inverse Proportions

Question

Pipes A and B can fill a tank in 12 mns and 15 mns If both are
opened together ,how much time will they take to fill it
completely?

Shridhar Kaushik · Accepted Answer

If pipe A can fill a tank in 12 minutes

⇒ In 1 minute, pipe A can fill $(\frac{1}{12})^{th}$ part of the tank

Similarly, in 1minute pipe B can fill $(\frac{1}{15})^{th}$ part of the tank

∴ The portion of the tank filled in 1 minute when both pipes are opened together $= \frac{1}{12} + \frac{1}{15} = \frac{5 + 4}{60} = \frac{9}{60}$

i.e. $(\frac{9}{60})^{th}$ part is filled in 1 minute

$∴ Complete tank will be filled in \frac{1}{(\frac{9}{60})} min i.e. \frac{60}{9} minute or 6 \frac{2}{3} minute.$

Pipes A and B can fill a tank in 12 mns and 15 mns.If both are opened together ,how much time will they take to fill it completely?