In January 2018 the Corner Construction Company started on a contract for the building of a school for the Free State government at a contract price of R2 000 000. It has been estimated that the work will last for the next 36 months. At 31 December 2019 the following information is available: 1. Opening and closing balances were as follows: 1 January 2019 31 December 2019 (R) (R) Material on site 5 000 Plant on site 340 000 14 000 280 000 Uncertified work 60 000 35 000 Salaries & wages (in arrears) Tools 10 000 6 000 65.000 2. Material purchased and delivered to site Tools purchased and sent to site Material destroyed by a fire R250 000 R100 000 R 10 000 R 28 000 Material returned to the store Salaries & wages paid on site R150 000 Rent of equipment R40 000 Water & electricity R18 000 Overheads (25% of the cost of material used) R15 000 Tools sold for cash (cost price R10 000) 3. During the year, architects' certificates to the value of R750 000 had been issued. Clients are entitled to a retention amount of 10% of all completed work certified by the architect. 4. During 2018, the previous financial year the following amounts appeared in the books: Cost of work certified Value of work certified Cash received from client R455 320 R580 000 R522 000 5. The cost to still complete the remainder of the contract is estimated to be R476 930. The total cost of the contract was estimated to be R1 500 000.