Vidyalelo
Aptitude · Q25

Time And Work

Competitive Exams · Aptitude · question 25

Q25

Two pipes A and B can fill a cistern in 12 min and 16 min respectively. Both the pipes are opened together for a certain time but due to some obstruction the flow of water was restricted to 7/8 of full flow in pipe A and 5/6 of full in pipe B. This obstruction is removed after some time and tank is now filled in 3 min from that moment. How long was it before the full flow.

Two pipes A and B can fill a cistern in 12 min and 16 min respectively. Both the pipes are opened together for a certain time but due to some obstruction the flow of water was restricted to of full flow in pipe A and of full in pipe B. This obstruction is removed after some time and tank is now filled in 3 min from that moment. How long was it before the full flow.
A.
8 min
B.
3 min
C.
5.6 min
D.
4.5 min
Answer
E.
None of these

Answer: Option D

Solution

Answer: Option D
Solution:
Let the obstruction remain for x min.
Hence,
Part of cistern filled in X min + part of cistern filled in 3 min = full cistern
     = 1

Thus,
X = 4.5 min.