Onandomba Pty (Ltd) provides skilled labour to the construction of low-cost apartments. They have recently been asked by a builder NHE to bid for a kitchen fitting contract for a new development of 600 identical apartments. Onandomba Pty (Ltd) has not worked for this builder before. Cost information for the new contract is as follows:

Labour for the contract is available. Onandomba expects that the first kitchen will take 24 man-hours to fit but thereafter the time taken will be subject to a 95% learning rate. After 200 kitchens are fitted the learning rate will stop and the time taken for the 200th kitchen will be the time taken for all the remaining kitchens. Labour costs N$15 per hour.

All overheads are absorbed on a labour hour basis. Onandomba Pty (Ltd) has collected overhead information for the last four months and this is shown below:

Overheads (N$)

Hour worked

January

115 000

9 300

February

113 600

9 200

April

116 000

9 400

May

116 800

9 600

Onandomba Pty (Ltd) normally works around 150 000 labour hours in a year.

Required: Calculate total labour hour that will be needed to complete the total 600 apartments.