The total area of a box is the sum of all the area of the faces it has. It is also called the surface area. The area of one face of a rectangular box is equal to the product of its length and width. So, the total area would be:
SA = 2lw + 2wh + 2lh
SA = 2(4)(3) + 2(3)(6) + 2(4)(6)
SA = 108 ft^2
A 15% percent markup means that the typewriter cost was increased by 15%, or 0.15 by moving the decimal 2 places to the left. If the original price was x, and 15% of it is 0.15*x, we can add them up to get 1.15*x=129.95. Dividing both sides by 1.15, we get x=113 dollars
5*2=10
10+12*4.5=64cm^2
Hope it helps