Ann’s cash at bank account for the month of May shows receipts from customers of £4,370 and payments to suppliers of goods for resale of £2,850. On 1 May and 31 May Ann owed suppliers £460 and £570 respectively and at 31 May one customer had not paid her invoice of £320. Ann had goods on hand at 1 May and 31 May which had cost him £650 and £710 respectively. Ann’s gross profit for the month of May is