Two pipes P and Q would fill an empty cistern in 24 minutes and 32 minutes respectively.

0 votes
1 view
asked May 15 in Class VIII Maths by priya12 (-11,279 points)

Two pipes P and Q would fill an empty cistern in 24 minutes and 32 minutes respectively. Both the pipes being opened together, find when the first pipe must be turned off so that the empty cistern may be just filled in 16 minutes.

Please log in or register to answer this question.

1 Answer

0 votes
answered May 15 by navnit40 (-2,750 points)

P’s one minute’s work = 1/24

Q’s one minutes work = 1/32

Let the first pipe must turn off after x minutes

The cistern filled in 16 minutes

Then P’s x minutes work + Q’s 16 minutes work = 1

⇒ (1/24) × x + (1/32) × 16 = 1

x/24 + ½ = 1

⇒ x/24 = 1 – (½) = ½

⇒ x/24 = ½

⇒ x = 24/2 = 12

∴ After 12 minutes pipe P would turned off

Related questions

...