Explanation:
To determine how many weeks it took for Tom to have 15 cards collected, we need more information about the growth rate of his collection. The given information states that by week 5, Tom had collected 12 cards, but it doesn't provide details about the rate of card collection.
If we assume that Tom's card collection grows at a constant rate, we can calculate the rate of card collection per week using the given information. By week 5, Tom had collected 12 cards. This means that on average, he collected 12/5 = 2.4 cards per week up to that point.
Using this average rate, we can estimate how many weeks it would take for Tom to have 15 cards collected. We'll divide the total number of cards (15) by the average rate of card collection (2.4 cards per week):
15 cards / 2.4 cards per week ≈ 6.25 weeks.
Therefore, it would take approximately 6.25 weeks (or 6 weeks and 3 days) for Tom to have 15 cards collected, assuming a constant growth rate.