Area of rectangular prism is given by:
A=2(wl+hl+lw)
where w=width h=height, l=length
checking for given options
1. 8 ft, by 4ft by 3ft
Area = 136 square feet
5. 3 feet by 5 feet by 7 feet
Area =142 square feet
so our first and last option matches the requirement of area less than 160 square feet.
385 + 326 + 298 = 1,009 / 3 = 336.33
385 + 326 + 298 + x = 350
350 x 4 = 1,400
1,400 - 1,009 = 391
385 + 326 + 298 + 391 = 1,400 / 4 = 350
The answer is $391
