Problem # 1. Solve step by spet a) and b).

a) Complete amount to be credited and balance outstanding:

Amount of invoice: $4500 Terms: 2/10, 1/15, n/30 Date of invoice: January 11 Paid February 4: $1800 Credited Amount: ? Outstanding Balance: ?

b). A Department Store paid its supplier $2500 for a Smart TV Set On January 8, the department store marked the Smart TV Set up 40% on selling price. As a special promotion, the department store marked the Smart TV Set down 20% on February 2 and market it 15% up on March 8. No one purchased the Smart TV Set, so the department store marked it up again 5% on March 15. What was the selling price of the Smart TV Set on March 15?

I need solution within an hour.. please solve it step by step.. Use formula