Difficulty Level: Easy
Stats: 3,699 / 5,655 ( 65.41% ) got this right

3 pumps, working 8 hours a day, can empty a tank in 2 days. How many hours a day must 4 pumps work to empty the tank in 1 day?

  • 8
  • 9
  • 10
  • 11
  • 12