A bank is getting a new marble floor that is green and white. The width of the floor is 8 feet. A white marble triangle will extend 10 feet into the area. White marble costs $9.50 per square foot. How much will the white marble section cost?

The answer is $380.

First find the area of the triangle. The area (A) of the triangle with base b and height h is:

A = b * h / 2

The width of the floor is the base of the triangle: b = 8 ft

The extension into the area is the height of the triangle: h = 10 ft

A = 8 * 10 / 2

A = 80/2

A = 40 ft²

The cost is $9.50/ft². So, the price of the white marble section is:

40 ft² * $9.50/ft² = $380