Melissa's fish tank has 18 liters of water in it. She plans to add 5 liters per minute until the tank has more than 58 liters. What are the possible numbers of minutes Melissa could add water?

Answer 1

This type of question is asking you to build an algebraic inequality. Start with what you know. You have 18 liters to start with , you are going to add 5 liters per minute, and you need more than 58 liters

take those 3 pieces and you have: 18 + 5m>58

now you need to solve for your variable(m)

first subtract 18 from both sides; this will leave you with 5m>40

now divide both sides by 5 which leaves you with m>8

so Melissa will be adding water for 8 minutes

Answer 2

Let x represent minutes.

The inequality derived from the question is...

58 > 18 + 5x

Solve for x...

58 > 18 + 5x

58 - 18 > 5x

40 > 5x

40/5 > x

8 > x

So it will take more than 8 minutes to have 58 liters.