A rectangular prism has length 8 cm, width 5 cm, and height 3 cm. Find its total surface area.

The total surface area of a rectangular prism is:
SA = 2(lw + lh + wh)

Substitute l = 8, w = 5, and h = 3:
SA = 2((8)(5) + (8)(3) + (5)(3))

Calculate each product:
SA = 2(40 + 24 + 15)

Add inside the parentheses:
SA = 2(79)

Multiply:
SA = 158

Therefore, the total surface area is 158 cm².