Final answer:
To find the percentage of cards still in Rose's possession, we calculate the ratio of the number of cards left to the number of cards bought and multiply by 100%.
Step-by-step explanation:
To find out what percent of the cards Rose still has, we need to first calculate the total number of cards she originally bought. According to the given information, she gave 5 cards to her sister and then sent 3 of the remaining cards. This means she had 8 - 5 - 3 = 0 cards left. To find the percentage, we use the formula: (number of cards left / number of cards bought) * 100%. In this case, the number of cards left is 2 and the number of cards bought is 8, so the percentage of cards still in her possession is (2 / 8) * 100% = 25%.