A cistern is normally filled in 8 hours but takes 2 hours longer to fill because of a leak in it's bottom. If the cistern is full, the leak will empty it in?
A16 hrsCorrect AnswerIncorrect Answer
B40 hrsCorrect AnswerIncorrect Answer
C35 hrsCorrect AnswerIncorrect Answer
D25 hrsCorrect AnswerIncorrect Answer
Solution
Filled in 1 hour = [if gte vml 1]>[if !vml]-->`1/8` [endif]--> part Filled in 1hour with leakage = `1/10` part Leakage in 1 hours = `1/8-1/10=2/(8xx10)=1/40` 40 hours. Alternate Solution: Let B is the leak, So A A+B 8 10 hrs LCM = 40 L Eff 5 : 4 So B's 1 hr work = 4-5= -1 units, Hence B will emplty 1 L in 1 hr So it will empty the whole tank in = 40/1= 40 hr