1) To calculate Total you need to add up everything from Monday to Saturday e.g. K3 =SUM(E3:J3)
2) To calculate the Revenue you need to multiply the Total number of songs sold by the Song Cost. e.g. L3 =D3*K3
3) To calculate iTunes Profit you need to work out 28% of Revenue e.g. M3 =(L3*28/100)