The second one and the fourth one.
Explanation:
As the problem states, it takes 166.5 gallons of water in 3 mins. Since it states it is a proportional relationship, we know that 166.5/3 is the number of gallons pumped in 1 minute. We can write this as g(the number of gallons) = 166.5/3 * m(the number of minutes) ! In additon, 166.5/3 is equivalent to 55.5, which gives us the second and the fourth equation correct!