The cost of one trading card obtained using the principle of proportionality is $0.21
Given the Parameters:
25 trading cards = $5.25
Let the Cost of one trading card = b
We could set up a proportional system to calculate the Cost of one trading card as
follows :
25 cards = $5.25
1 card = b
Cross multiply:
25b = $5.25
Divide both sides by 25 to isolate b
25b/25 = 5.25 / 25
b= $0.21
Therefore, one trading card costs $0.21