Mojo Ltd manufactures pond pumps in batches of 400. During April, Batch no. 145 had a slight manufacturing fault, resulting in only 390 pumps being completed. The remainder was scrapped. Costs were: raw materials £2,000, labour and overheads £3,000. What was the cost per pump?

(a) £12.82

(b) £12.50

(c) £500

(d) £10