Question

Lucy's fish tank has 14 liters of water in it. She plans to add 5 liters per minute until the tank has at least 49 liters. What are the possible numbers of minutes

Lucy could add water?
Use t for the number of minutes.
Write your answer as an inequality solved fort.​

Answer 1

V = 14 + 5t

14 + 5t ≥ 49

Lucy has to add water at least for 7 minutes.

Explanation:

There were 14 liters of water in Lucy's fish tank. She was about to add water at the rate of 5 liters per minute until there were at least 49 liters of water in the tank.

If t represents the number of minutes she adds water and V is the volume of water in liters in the fish tank, then we can write the equation as

V = 14 + 5t ........... (1)

Now, this volume of water in the tank V must be at least 49 liters.

So, 14 + 5t ≥ 49 is the required inequality.

⇒ 5t ≥ 35

⇒ t ≥ 7

So, Lucy has to add water at least for 7 minutes. (Answer)