Question

Martha made earrings to sell at a craft fair. Her booth rental is $35 a day. Each pair of earrings costs $2 to make, and she sells them for $5 per pair. Martha wants to make at least $200 profit for the day. How many pairs of earrings must she sell to reach her goal?

Answer 1

She has a fixed cost $35 for the day.
Then on each pair of earrings, she spends $2.
Her costs are fixed $35 and $2 per pair of earrings.

She sells each pair of earrings for $5.
Her earnings are $5 per pair of earrings.

Let x = the number of pairs of earrings she sells in one day


`5x - 35 - 2x \ge 200`


`3x - 35 \ge 200`


`3x \ge 235`


`3x \ge 78.333...`

Since she must sell a whole number of pairs of earrings, she must sell at least 79 pairs of earrings.