Two taps A and B can fill a cistern in 12 hours and 18 hours respectively. In the beginning. Both taps are opened but after 4 hours first tap is turned off. Hiw much longer will the tank take to fill?
Answers
Answer:
It will take 12 hours to fill the tank
Step-by-step explanation:
If the taps where left open together to fill the tank, time taken would be,
1/12 + 1/18,
where 1 represents the tank being full,
Now, the question says that tap A is turned off after 4 hours later,
Hence, 4/12 + x/18 = 1 (x = time for which tap B is open, which is from the starting)
1/3 + x/18 = 1
x = 12 hours
Answer:
8 hrs more will be taken to fill Tank
Step-by-step explanation:
Tap A can fill in 12 hours
Tap A can fill in 1hr = 1/12
Tap B can fill in 18 hours
Tap B can fill in 1 hr = 1/18
Tap A & Tap B together can fill in 1hr = 1/12 + 1/18
= (1/36)(3 + 2)
= 5/36
Tap A & Tap B together can fill in 4 hrs = 4 * 5/36 = 5/9
Remained to fill = 1 - 5/9 = 4/9
Tap B can fill 1 in 18 hrs
4/9 can filled by Tap B in = 18 * 4/9 = 8 hrs
8 hrs more will be taken to fill Tank