Question

Molly bought a case of bottled water at the store. The case contains 48 bottles. Molly knows that she will drink 3 bottles of water each day and plans to restock her supply of water once she has fewer than 10 bottles left. Determine which inequality is used to find the number of days, x, before Molly will need to restock her supply of bottled water

Answer 1

Let x = number of days before Molly will need to restock
48 - 3x < 10 we use is less than because "has fewer than" 

If you solve this inequality by subtracting 48, then dividing by -3 (switch inequality sign), you get x > 12$\frac{2}{3}$

Answer 2

48 - 3x < 10, x=13

13 days