An electrical supplies store sells 140 power stabilizers . .

We are looking for the selling price per unit: let's call that x.

We know that profit = sales price - cost. This means that per unit, the profit is: $$x-16$$

We also know that the store sells 140 units per week, making their total weekly profit $$140\left(x-16\right)$$

We want the weekly profit to be at least $5600, or $$140\left(x-16\right)\le5600$$

Solving for x gives $$x-16\le40$$ $$x\le56$$

So the selling price per unit must be at least $56, or answer choice D.

Vincen wrote:An electrical supplies store sells 140 power stabilizers every week. If each power stabilizer costs the store $16, what is the minimum selling price per unit that will ensure a weekly profit of at least $5600 from sales of power stabilizers?

A. 24
B. 26
C. 40
D. 56
E. 60

We use the profit formula: revenue - cost = profit. We can create the following inequality in which n = selling price per unit:

140n - 140 x 16 ≥ 5600

140(n - 16) ≥ 5600

n - 16 ≥ 40

n ≥ 56

Answer: D

Vincen wrote:An electrical supplies store sells 140 power stabilizers every week. If each power stabilizer costs the store $16, what is the minimum selling price per unit that will ensure a weekly profit of at least $5600 from sales of power stabilizers?

A. 24
B. 26
C. 40
D. 56
E. 60

We use the profit formula: revenue - cost = profit. We can create the following inequality in which n = selling price per unit:

140n - 140 x 16 ≥ 5600

140(n - 16) ≥ 5600

n - 16 ≥ 40

n ≥ 56

Answer: D