You have a 1.5 litre bottle of water and drink 295 millilitres. Your friend drinks 135 millilitres. How much water is left?

First you convert 1.5 liters to milliliters which is 1500 then you subtract 295 and that equals 1205 milliliters and subtract you friend drank amount which is 135 milliliter and that equals 1070 milliliter so you have 1.07 liters left.