Final answer:
Marcus should share with his school friends because 198 is a divisor of the 900 pieces of candy.
Step-by-step explanation:
In order for Marcus to share the candy evenly, he needs to find a number that can be divided by both 11 and 18 without any remainder. This number is called the least common multiple (LCM) of 11 and 18. To find the LCM, we can list the multiples of both 11 and 18 and find the smallest number that appears in both lists.
The multiples of 11 are: 11, 22, 33, 44, 55, 66, 77, 88, 99, 110...
The multiples of 18 are: 18, 36, 54, 72, 90, 108, 126, 144, 162, 180...
The LCM of 11 and 18 is 198. Since the bag of candy has 900 pieces, Marcus should share it with his school friends, as 198 is a divisor of 900. This means that each person in his school group can get their fair share of 900 pieces of candy.