A store is selling candy for $8 for 16 bags. How much will it cost if you need to have 84 bags?

16 bags are $8. However, you need more than 16 bags; you need 84.

So the first thing you do is divide 84 by 16 which is 5.25. This means that if 16 bags are $8, then you need to multiply the price and quantity by 5.25 to work out how much it is for 84 bags:

$8 = 16 bags

Multiply by 5.25:

$8 * 5.25 = 16 bags * 5.25

$42 = 84 bags

Therefore, it'll cost $42 to buy 84 bags.