Given:
Budget = $30
cost of pizza = $9
cost of drinks = $1
number of pizza = p
number of drinks = d
pizza and drinks should only be equal to or less than the budget of $30.
$9p + $1d < $30
unit cost of pizza : 9
unit cost of drinks : 1
total cost of set (p & d) 10
pizza = 9/10 x 30 = 27 total cost of pizza
drinks =1/10 x 30 = 3 total cost of drinks
27 ÷ 9 = 3 number of pizzas to order
3 ÷ 1 = 3 number of drinks to order
To check:
9p + 1d < 30
9(3) + 1(3) < 30
27 + 3 < 30
30 < 30
