What is 25 off. and pound18.00 pounds?

To calculate £25 off £18.00, you would subtract £25 from £18.00. However, since £25 is greater than £18.00, this effectively means that the total after the discount would be £0, with £7.00 still remaining as the discount. Therefore, you cannot apply a £25 discount to an £18.00 price without ending up with a negative value.