Question 19
A pipe can fill up an empty tank in 18 hours. A full tank can be emptied by a pump in 20 hours. How long (in hours) will it take to fill up an empty tank if both the pipe and the pump are turned on at the same time?
Interpretation for this question: Use constant inlet and outlet rates, with no delay or other loss, as in the source model.
Answer format: enter the whole-number answer without units. Leading zeros are optional (the original paper uses four-digit answer boxes).
Interpretation for this question: Use constant inlet and outlet rates, with no delay or other loss, as in the source model.
Answer format: enter the whole-number answer without units. Leading zeros are optional (the original paper uses four-digit answer boxes).