Noah bought 15 baseball cards for $9.00. Assuming each baseball cards costs the same amount, how much will 12 baseball cards cost?

Answer:$7.20

Step-by-step explanation: Using the idea of proportion

15 base ball cost $9.00

12 base ball cost $x

i. e

15 = $9.00

12 = $x

Then we cross multiplied

15 * x = 12 * $9.00

15 * x = $108

Then we divide bothside by 15

x = $105/15

x = $7.2

First, we find how much 1 baseballs card costs.

1 card = 0.60

12*0.6 = $7.20