let “x” be the total volume of the container, then we know:

(1/4)x + 2240 = (5/6)x

find a common denominator:

(3/12)x + 2240 = (10/12)x

rearrange the formula to get “x” on one side:

2240 = (7/12)x

divide by (7/12) on both sides (which is the same as multiplying by (12/7)):

2240(12/7) = x

x = 3840

The total volume of the container is 3840ml.