Answer:
Store C
Explanation:
store a is selling 10 pencils for $2.50
$2.50 divided by 10 is 25 cents
so the price for store a is 25 cents per pencil
store b is selling 50 pencils for $6.00
$6.00 divided by 50 is 12 cents
so the price for store b is 12 cents per pencil
store c is selling 100 pencils for $8.25
$8.25 divided by 100 is 8.25 cents
obviously you can't give someone .25 cents so round it down to 8
so the price for store c is 8 cents per pencil
store d is selling 250 pencils for $21.25
$21.25 divided by 250 is 8.5 cents
which rounds up to 9 cents per pencil
Store c has the lowest price for one pencil