Each pack of batteries cost $21 each.
And then you have $63.
The operation to be used: Division.
63 ÷ 21 ==
Answer: 3
= You can buy 3 packs of batteries with your $63.
You have to multiply the original price by 1/3 and then multiplying it by 2:
y=1/3x(2)
y=1/3(28.5)(2)
y=9.50(2)
y=19
$19.5
This is 2/3 of the original price (1/3 off).
Hope I helped...
