Answer: In 1 hour water flowed out = 74/17 gallons
Explanation:
Given as ,
The quantity of water flowed out of tank = 18 1/2 gallons
 = 37/2 gallons
The time spend in flowing water out of tank = 4 1/4 hours
 = 17/4 hours
∵ In 17/4 hours , water flowed out = 37/2 
∴ In 1 hours , water flowed out = 
So, in 1 hour water flowed out = 37*4/17*2 gallons Answer