Mathematics
Medium
Question
pipes P and Q would fill a cistern 18 and 24 minutes respectively. Both pipes being opened, find when the first pipe must be turned off so that the cistern may be just filled in 12 minutes?
A
after 12 mins
B
after 9 mins
✓ Official correct answer
C
after 8 1/2 mins
D
after 10 mins
Community credibility
Registered members can vote for the answer they believe is correct today and explain why. If the facts change after an election or news event, suggest a new option so others can vote it up.
A
after 12 mins
No member explanations yet for this option.
B
after 9 mins
No member explanations yet for this option.
C
after 8 1/2 mins
No member explanations yet for this option.
D
after 10 mins
No member explanations yet for this option.