Question

Janie has $3. She earns $1.20 for each chore she does and can do a fraction of chores. She wants to earn enough money to buy a CD for $13.50

Write an inequality to determine the number of chores, c, Janie could do to have enough money to buy the CD.

Answer 1

13.50 = 3 + 1.20x

The amount $13.50 is how much money Janie needs to buy the CD. 3 ($3) is the amount she already has. x represents each chore she does, and $1.20 is the amount she receives for doing that chore.

Answer 2

`1.20c+3\ge13.50`

Explanation:

Let us call c the number of chores that Janie can do.

The money that Janie can earn with c chores is the product of that number of chores times the money earned with each chore $1.20, so:

1.20c

The total money that Janie can get is the money she earns doing chores plus the $3 which is the money she already has. Therefore:

1.20c+3

The total money that Janie can get should be at least the price of the CD $13.50, so the total money Janie can get should be greater or equal than $13.50. Therefore the inequality to determine the number of chores, c, Janie could do to have enough money to buy the CD is:

`1.20c+3\ge13.50`