At A3 V auto repair shop, we paid 300 EUR for car repairs. In this amount, 240 EUR is for materials. How much did they charge for one working hour, if the repair took $\frac{3}{4}$ of an hour?
(A) 30 EUR
(B) 45 EUR
(C) 60 EUR
(D) 80 EUR
(E) 100 EUR

![](https://cdn.mathpix.com/cropped/2024_06_07_64c08af683227112c601g-2.jpg?height=654&width=585&top_left_y=958&top_left_x=1318)
A3. From the equation $\frac{3}{4} \cdot x+240=300$ we calculate the unknown value of the working hour $x=80$ EUR.