Question

Alex stocks up for winter. He buys 36 cans of vegetables. He pays 80 cents per can for tomatoes and 40 cents per can for corn, for a total cost of $20.8. How many tomatoes does he buy??

Answer 1

Let tomatoes be as x and corn be as y.
Total cans is 36 cans.
$20.8 = 2080 cents

1. x + y = 36
2. 80x + 40y = 2080

From equation 1, we get
y = 36 - x

Substitute into equation 2,
80x + 40(36 - x) = 2080
80x + 1440 - 40x = 2080
40x = 2080 - 1440
x = 640 ÷ 40
x = 16

x + y = 36
16 + y = 36
y = 36 - 16
y = 20

Alex does buy 16 tomatoes.