Question

Tom bought 24 baseball cards for $50.00. Cheap cards are $1.00 each and expensive cards are $3.00 each. Determine how many cheap cards Tom bought. Determine how many expensive cards Tom bought.

Answer 1

let x = number of cheap cards

y = number of expensive cards

x + y = 24 ( equation 1 )

(1)(x) + (3)(y) = 50

x + 3y = 50 ( equation 2 )

equation 2 - equation 1

(x + 3y) - ( x + y ) = 50 - 24

x + 3y - x -y = 26

2y = 26

y = 26/2

y = 13 expensive cards

x + y = 24

x + 13 = 24

x = 24 -13

x = 11 cheap cards

verification :

x + 3y = 50

11 + 3(13) = 50

11 + 39 = 50

50 = 50

correct.

the final answer

11 cheap cards

13 expensive cards