Answer:
72.5%
Step-by-step explanation:
(The total number of cards - 40 / Number completed - 29)
1. 40 = 100%
2. Divide both sides of the equation by 40 to get 1 on the right side (40/40 = 1) (100%/40 = 2.5%)
3. multiply both sides of the equation by 29 to find the percentage of cards completed (1*29 = 29 cards finished) (2.5%*29 = 72.5%)
4. Answer: Elin has completed 29 cards which is 72.5% of 40