A cistern can be filled by a tap in 3 hours while it can be emptied by another tap in 10 hours. If both the taps are opened simultaneously, then after how much time will the cistern get filled?
Choose the most appropriate option:
A) 4.3 hrs B) 8.9 hrs C) 2.9 hrs D) 7.2 hrs E) 8.6 hrs
Net part filled in 1 hour = (1/3 - 1/10)   = 7/30   The cistern will be filled in 30/7 hrs i.e., 4.3 hrs.   4.3 hrsnswer:4.3 hrs
<result>A</result>
A cistern can be filled by a tap in 3 hours while it can be emptied by another tap in 10 hours. If both the taps are opened simultaneously, then after how much time will the cistern get filled?