Answer:9400 backpacks
Step-by-step explanation
since the number of packs to be sold in a is represented by x,
selling price for 1 week = 35x
cost price for 1 week = 15x
profit = 35x-15x = 20x
additional cost of production = 11,000
this implies that 20x - 11,000 7800
20x - 11,000 7,800
20x 7800+ 11000
20x 18,800
x 18800/2
x 9,400
at least 9,400 packs have to be sold each week to make a profit of $7800
