When 200 gallons of oil were removed from a tank, the volume of oil left in the tank was $$\frac 3 7$$ of the tank`s capacity. What was the tank`s capacity?

(1)Before the 200 gallons were removed, the volume of oil in the tank was $$\frac1 2$$ of the tank`s capacity.

(2)After the 200 gallons were removed, the volume of oil left in the tank was 1,600 gallons less than the tank`s capacity.