Answer: There are 14 gallon jugs and 10 half gallon jugs.
Explanation:
Since we have given that
Total number of jugs = 24
Let the number of gallon jugs be 'x'.
Let the number of half gallon jugs be '24-x'.
Total gallons of milk = 19
According to question,

So, Number of gallon jugs be 14 and number of half gallon jug be 24-14=10.
Hence, there are 14 gallon jugs and 10 half gallon jugs.