Question

Laura’s fish tank has 17 liters of water in it. She plans to add 5 liter per minute until the tank has more than 72 liters. What are the possible numbers of minutes Laura could add water ? Use t for the number of minutes. Write your inequality solved for t.

Answer 1

t= number of minutes

Multiply 5 liters by number of minutes (t), then add the 17 liters already in the tank. This totals 72 liters or more.

17 + 5t ≥ 72
subtract 17 from both sides

5t ≥ 55
divide both sides by 5

t ≥ 11 minutes


ANSWER: Laura could add water for 11 minutes to be sure the tank has 72 liters or more.

Hope this helps! :)