Tank 1: v = 1540 - 6m
Tank 2: v = 236 + 6m
109 minutes, less than two hours, since two hours is 120 minutes (60 minutes in one hour, times 2)
Set them equal to each other to find out when they will have the same number of gallons: 1540 - 6m = 236 + 6m
1304 = 12m
108.667 rounded to the nearest minute is 109 minutes, which is the answer.