First, figure out how many total cookies you need. You do this by multiplying the number of friends times the number of cookies each friend will get.
8 x 3 = 24
Then, you take the number of cookies and divide it by the number in each box to find the number of boxes you need.
24/6 = 4
Quan should get 4 boxes.
2,400
20% of 3,000= 600
3,000 - 600= 2,400