Solution:
We are given that
Ballpoint pens cost $1.50 a dozen for the first 200 dozen a store buys from a wholesaler.
$1.25 a dozen for those bought in addition to the first 200 dozen.
we have been asked to find
If the store buys 250 dozen pens from the wholesaler, then what is the average cost of ballpoint pens per dozen.
Cost of first 200 dozens of pens

Cost of 50 dozens of pens

Total cost of 250 dozens of pens

Average cost per dozen
