Marnie opens a bag of chips and eats 5 of them to see if she likes them. She does, so she eats 5 more. The bag has 100 chips in it and starting on the second day she has them, Marnie eats 10 each day. How many days does it take for Marnie to eat the whole bag of chips? Think carefully first, then make a decision:
Marnie has already eaten 5 of the chips + 5 more = 10 chips Marnie ate. The bag has 100 chips in it and Marnie has only eaten 10, 100 - 10 = 90 chips left. If Marnie eats 10 chips a day starting from the second day she has them, it will take her 90 chips in the bag / 10 chips Marine eats a day = 9 days to eat the whole bag. However, Marnie also ate chips on the first day she bought them, so 9 + 1 = 10 days to eat the whole bag. So, the answer is 10.