A water tank has two taps (Tap-1 and Tap-2). Tap-1 can fill a tank in 8 hours and Tap.2.can empty the tank in 16 hours. How long will they take to fill the tank if both taps are opened simultaneously but Tap-2 is closed after 8 hours?

A water tank has two taps (Tap-1 and Tap-2). Tap-1 can fill a tank in 8 hours and Tap.2.can empty the tank in 16 hours. How long will they take to fill the tank if both taps are opened simultaneously but Tap-2 is closed after 8 hours?

(a) 10

(b) 12

(c) 14

(d) 16

Answer: 12

Solution:

Tap-1, fills in 1 hr =  1/8

Tap-2, empties in 1 hr = 1/16

When both taps are open, the tank fills in 1 hr = (1/8 – 1/16) = 1/16

In 8 hrs, the tank fills =  1/16 ×৪ = ½

Remaining = 1 – ½ = ½

½ is filled by only Tap 1

1/8 is filled by Tap-1 in 1 hr

So, ½ is filled by = (1×8)/2= 4 hr

Total time = 8+4 = 12 hr
A water tank has two taps (Tap-1 and Tap-2). Tap-1 can fill a tank in 8 hours and Tap.2.can empty the tank in 16 hours. How long will they take to fill the tank if both taps are opened simultaneously but Tap-2 is closed after 8 hours? A water tank has two taps (Tap-1 and Tap-2). Tap-1 can fill a tank in 8 hours and Tap.2.can empty the tank in 16 hours. How long will they take to fill the tank if both taps are opened simultaneously but Tap-2 is closed after 8 hours? Reviewed by Admin on 9:23 AM Rating: 5

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