A storex jug was 4/5full of water when the gauge indicated 72 litres.what was the full capacity of the storex jug.

Let x be the full capacity of the storex jug.

Given that the jug was 4/5 full of water, this means that 1/5 of the jug was empty.

So, if 1/5 of the jug is empty, this means that 1 - 4/5 = 1/5 is equal to 72 litres.

Therefore, we can set up the following equation:
1/5x = 72

Multiplying both sides by 5 to solve for x, we get:
x = 5 * 72
x = 360

Therefore, the full capacity of the storex jug is 360 litres.