4a.
We can get the least number by taking LCM of 24 and 16.
We list each of the numbers as prime factors and take the mutiplication of each unique prime factor that occurs the greatest number of times.
24 = 2 * 2 * 2 * 3
16 = 2 * 2 * 2 * 2
So,
2 occurs four times
3 occurs 1 times
LCM of 24 and 16 is:
2 * 2 * 2 * 2 * 3 = 48
Least number of cheese and cracker appetizer = 48
4b.
Sleeves are sold in 24.
So, to get 48, she would need to buy:
48/24 = 2 sleeves
4c.
Cheese slices comes in packages of 16. So she needs to buy:
48/16 = 3 packages of cheese