can you show me how to calculate cash flow lost for this problem?

Part 1: Order Fill Rate

Firm A faces the following:

100 units per order

3000 orders per year

Pre-tax profit per unit = $250

75% of incomplete orders backordered; 25% cancelled

Backorder costs per backorder = $200

Invoice deduction per backordered order = $300

1. What is the total lost profit or cash flow at an 85% order fill rate?