The amount of water in a bottle is reduced by 85% to 120 milliters how many water was originally in the bottle.

Given:

Rate of reduction : 85%

Remaining volume: 120 ml.

This means that 120 ml is equivalent to 15% of the original volume.

100% - 85% = 15%

120 ml : 15% = 800 ml.

There was 800 ml of water before it was reduced.

800 ml * 85% = 680 ml ⇒ volume reduced

800 ml - 680 ml = 120 ml ⇒ volume left after reduction.