Reggie DEBT

[roy82x]

Here is the breakdown for Reggie's debt:

Trip Cost: $500.00
Payment: $100.00 on 03/03/2006
Payment: $180.00 on 03/18/2006
Payment: $120.00 on 04/16/2006

Subtotal Trip: $100.00 (for base cost of trip only/unpaid portion)

Universal Studios Admission Ticket Cost: $49.00
Payment: $0.00
Tax: 3.67 (7.5% Sales Tax)

Subtotal Universal: $53.00 (unpaid portion)

Grand Total: $153.00<- (How much you owe me)

Should I start charging interest?