|A) 6:7||B) 7:6|
|C) 7:54||D) None of these|
The number of days required by a single kirlosker pump to fill the tank = 6 x 7 =42 days and the number of days required by a single USHA pump to fill the same tank = 2 x 18 =36 days.
Now , since efficiency is inversely proportional to the number of days. Hence,