Explain how to solve this math problem: Roger goes to the store to buy some coffee.  The normal brand of coffee he buys cost $5 per pound.  He had to buy a more expensive brand that cost 20% more since his favorite brand was sold out.  He decides to buy a week's worth of coffee and he uses 1 pound of coffee per day.  He also decided to buy himself a donut for $2.  How much did everything cost?