Answer:
630,630 different arrangements are possible for the given laptops.
Step-by-step explanation:
Total number of laptops = n = 15
Number of identical Dell laptops = 6
Number of identical Chromebooks = 4
Number of identical Mackbooks = 5
We have to find in how many ways can the laptops be arranged. Number of arrangement of objects is calculated using Permutations as the order of objects matter during the arrangement. The formula to calculate the number of possible arrangements when there are similar objects is given as:

Here n is the total number of objects and a,b, and c represent the number of identical objects. Using the given values we get:

This means 630,630 different arrangements are possible for the given laptops.
For #1
city A's mean would be 10.5, then you would divide it by the number of numbers there is which is 5,So 10.5/5 is 2.1
city B's mean would be 11.6 then you would divide it by the number of numbers there is which is 5, So 11.6/5 is 2.32.
thats all I have don't know how to do #3 sorry
Answer:
70
Step-by-step explanation:
39+5=44
100-44=56
56 percent of 125 is 70