![Two pipes A and B can fill a cistern in 16 and 24 minute respectively both fill pipes are opened together but 4](https://www.gkseries.com/blog/wp-content/uploads/2024/04/Two-pipes-A-and-B-can-fill-a-cistern-in-16-and-24-minute-respectively-both-fill-pipes-are-opened-together-but-4.jpg)
Two pipes A and B can fill a cistern in 16 and 24 minute respectively both fill pipes are opened together but 4 minutes before the cistern take to fill pipe B is closed. In how much time the cistern will get filled.
(a) 13 min
(b) 57/5min
(c) 11 1/5 min.
(d) 10 min
Sol:
![](https://www.gkseries.com/blog/wp-content/uploads/2024/04/image-275-1024x557.png)
In 4 min B can fill = 2 × 4 = 8 unit
![](https://www.gkseries.com/blog/wp-content/uploads/2024/04/image-276-1024x134.png)