the same lamp is a different price at two different stores. store pqr offers 5 of these lamps for $15.00…

Explanation:

Step1: Calculate unit - price for Store PQR

To find the unit - price, divide the total price by the number of lamps. For Store PQR, the total price is $15.00 and the number of lamps is 5. The unit - price formula is $u=\frac{T}{n}$, where $u$ is the unit - price, $T$ is the total price, and $n$ is the number of items. So, $u_{PQR}=\frac{15}{5}=3$ dollars per lamp.

Step2: Calculate unit - price for Store LMN

For Store LMN, the total price is $17.50 and the number of lamps is 7. Using the unit - price formula $u=\frac{T}{n}$, we have $u_{LMN}=\frac{17.5}{7}=2.5$ dollars per lamp.

Step3: Compare unit - prices

Compare $u_{PQR}=3$ and $u_{LMN}=2.5$. Since $2.5<3$, Store LMN has the lower unit price.

Answer:

Store LMN has the lower unit price because its unit price is $2.5$ dollars per lamp while Store PQR's unit price is $3$ dollars per lamp.