Question

a cup of tea costs 10 cents less than a cup of coffee, while a cup of hot chocolate costs 20 cents more than a cup of coffee. three cups of coffee, five cups of tea and two cups of hot chocolate cost 8.90 dollars. What is the price of a cup of coffee?

Answer 1

$0.90

Explanation:

Given tea is 10 cents less, and chocolate is 20 cents more than a cup of coffee, you want to know the price of a cup of coffee when 5 teas, 3 coffees, and 2 chocolates cost $8.90.

Setup

Let c represent the cost of a cup of coffee (in cents). Then tea is (c-10) and chocolate is (c+20). The total purchase is ...

5(c -10) +3c +2(c +20) = 890 . . . . . . . cents

Solution

Simplifying the equation, we have ...

10c -10 = 890

c -1 = 89 . . . . . . divide by 10

c = 90 . . . . . . . add 1

The price of a cup of coffee is $0.90.