A store sells the basic model of a phone for $60 and the upgraded model for $200. It costs the store $10 to buy each basic model and $50 to buy each upgraded model from the phone company, On Tuesday, the store has $1,800 in
sales for these two models, and it paid the phone company $400 to buy these phones. How many upgraded models
did the store sell on Tuesday?
O 6 upgraded phones
10 upgraded phones
15 upgraded phones
42 upgraded phones