<span>Find the area of two sides (Length*Height)*2 sidesFind the area of adjacent sides (Width*Height)*2 sidesFind the area of ends (Length*Width)*2 ends<span>Add the three areas together to find the surface area</span></span>
A suitable statistics calculator gives the probability that 6 or more show up as being about ...
0.2539
B = 100(1 + 0.04)^12 = 100(1.04)^12 = 100(1.601) = $160.10