A worker is paid differential piecework. The scheme is as follows: Units per day Up to 50 51-70 Units per day 71-80 Units per day 81 - 100 Units per day N50 per unit N60 per unit N65 per unit N70 per unit His daily outputs for a five day week were 68 units, 83 units, 59 units, 94 units and 47 units. What will be his gross pay for the week?