Problema Solution
On Monday, Archie paid $3.40 for three doughnuts and two coffees. On Tuesday he paid $3.60 for two doughnuts and three coffees. On Wednesday he was tired of paying tab so he went out to coffee by himself. What was his bill for one doughnut and one coffee?
Answer provided by our tutors
let
x = the price of one doughnut
y = the price of one coffee
Archie paid $3.40 for three doughnuts and two coffees
3*x + 2*y = 3.40
$3.60 for two doughnuts and three coffees
2*x + 3*y = 3.60
by solving the system of equations
3*x + 2*y = 3.40
2*x + 3*y = 3.60
we find
x = $0.6
y = $0.8
the bill for 1 doughnut and 1 coffee is 0.6 + 0.8 = $1.4.