A shop increases the price of a television by 20%. In a later sale, it decreases the new price by 20%.
(a)Using p pounds for the original price, show that the final price is 0.96p pounds, and state the overall percentage change.(3)
(b)Explain why the overall change is not 0%, even though one percentage is an increase of 20% and the other is a decrease of 20%.(1)
(Total for Question 15 is 4 marks)