It is a simple question where finding out the increase of 399 pound by 26.5% is required. The answer needs to be rounded off to the nearest penny.
So
Total amount of increase = 399 * (26.5/100)
= 10573.5/100
= 105.735
So increase of 399 pound by 26.5% gets to = (399 + 105.735) pounds
= 504.735 pounds
Noew this amount has to be rounded to the nearest penny and so the amount becomes 504.74 pounds.