We know that the new price of 33 pounds is a 75% of the initial price (because 100% - 25% sale = 75%). So we can write it down as:
33 = 75% from x
33 = 75/100x
33 = 3/4x / * 4 (both sides)
132 = 3x / ÷ 3 (both sides)
x = 44
Answer: The initial price was 44 pounds.