Question

Two taps A and B fill a cistern in 24 min and 30 minutes respectively.Both the pipes are opened together. find when the pipe B must be turned off so that the cistern may be full in 18 minutes.​

Answer 1

Solution will may help you...

Answer 2

ANSWER:

Let the total capacity of the tank be the LCM of 24 and 30

24 = 2³ × 3

30 = 2 ×  3 × 5

So,

LCM = 2³ × 3 × 5

LCM = 120

So,

Tap A fills the cistern in 120/24 = 30/6 = 5 minutes

Tap A fills the cistern in 130/30 = 12/3 = 4 minutes

Now,

(5 × 18 + 4 × x ) = 120

90 + 4x = 120

4x = 30

x = 30/4 = 7.5 minutes

x = 7.5 minutes

So, the Pipe/ Tap B must be turned off after 7.5 minutes it was opened

I hope my answer was helpful. Do mark as BRAINLIEST.