Hi there,
Recall how 7 packs for gum sell for $29.33.
Before we can calculate how much it would cost to sell 3 packs of gum, we must calculate how much it would first cost to sell 1 pack of gum.
The cost of 1 pack of gum is the current total cost divided by the total amount of gum packs you receive at that price.
In this case, the total cost is $29.33, and we receive 7 gum packs at that price.
Therefore, the cost of 1 pack of gum is , which equates to $4.19.
We now know that each pack of gum costs $4.19.
Hence, 3 packs of gum would cost three times that price.
The cost of 3 packs of gum is $12.57.
Hope that helps!