Answer : The time taken will be 25 min.
Explanation :
First we have to determine the amount of fluid.
As, 1 mL contains 30 gtt
So, 500 mL contains

Now we have to determine the time taken.
As, 60 gtt takes time = 1 min
So, 1500 gtt takes time =

Therefore, the time taken will be 25 min.