Q: Lloyd, Mark, and Michael have their Pokemon cards collection. Currently, Mark has thrice as many cards as Lloyd but has 10 fewer cards than Michael. If Michael has 100 cards now, how many more cards should they collect so that all three of them will have a total of 300 cards?
A: 80
Explain how we arrive at this answer:
Explanation: Mark has 10 fewer cards than Michael so Mark has 100 cards - 10 cards = 90 cards. So, Lloyd has 90 cards / 3 = 30 cards. All three of them have 90 cards + 30 cards + 100 cards = 220 cards. Thus, they need to collect 300 cards - 220 cards = 80 more cards.