I say 1/6 Gal is your answer.
Answer:
7 + 6 = 13
13 = 7 + 6
13 – 6 = 7
7 = 13 – 6
Step-by-step explanation:
7 + 13 = 20
13 + 7 = 20
13 – 13 = 0
13 – 0 = 13
7 + 0 = 7
6 + 0 = 6
13 – 0 = 13
13 – 13 = 0
7 + 0 = 7
6 + 0 = 6
13 – 0 = 13
13 – 13 = 0
7 + 6 = 13
13 = 7 + 6
13 – 6 = 7
7 = 13 – 6
Step-by-step explanation:

I got you- The answer is (B. 4) hope this helps, if you need me to explain ask in the comments. Have a good day/night:)