Harry is building a pond for his local park. He wants to put a border made of pebbles around the pond. The border will be 10 cm wide and is shown on the diagram by the shaded area. Pond Border 2 m Pebbles are sold in packs that cover 100 cm2 and cost £4.80 each. (a) How much will it cost Harry to buy the pebbles that he needs?​