Question

Keisha's fish tank has 13 liters of water in it. She plans to add 4 liters per minute until the tank has at least 41 liters. What are the possible numbers of minutes Keisha could add water? Use t for the number of minutes. Write your answer as an inequality solved for t.

Answer 1

7≥t

Explanation:

The tank already has 13litres of water in it.

Keisha plans on increasing the quantity of the water to 41 litres. Hence,

41 litres - 13litres = 28litres

The above implies that she needed 28litres to be added to the fish tank.

She adds 4 litres per minute

Now, the question can now be reframed as how many minutes will be needed to add 28litre.

Considering to proportion method

4litres = 1 minute

28litres = t minutes

4litres × t minutes = 28litres

t = 28/4

t = 7 minutes

Hence, at least 7 minutes will be needed to increase the quantity of the tank water from 13litres to 41litres

But since we are to write the answer in an inequality form.

41≥ 13+4t

Solve for t

41≥13+4t

41-13≥4t

28≥4t

Divide both sides by 4

28/4≥4t/4

7≥t