Surface area is the sum of the areas of all faces (or surfaces) on a 3D shape. A cuboid has 6 rectangular faces. To find the surface area of a cuboid, add the areas of all 6 faces. We can also label the length (l), width (w), and height (h) of the prism and use the formula, SA=2lw+2lh+2hw, to find the surface area.
You have 5 quarters which equals 25 cents each. Which in total comes to $1.25. You have 15 dimes which is worth 10 cents each. Which in total comes to $1.50. $1.50 +$1.25 =$2.75