Answer:
1
Step-by-step explanation:
I beileve it would be 1 because if you grab the 15 gallons and mutiply them by 4, then you would get 60. There is 60 seconds in a minute therefore, I would take the quarts and divde them by the seconds. Then I would get my answer of 1 quart per second.
Hope this helped. If you still do not understand I will gladly explain it more. If im wrong, feel free to correct me. :)