Need help with problems 1-3.

Formula for surface are: 2(lw+wh+lh) where l is length, w is width and h is height.
Plug in for 1 - 3
1:
2((16)6 + (6)5 + (16)5)
2(96 + 30 + 80)
2(206)
412 ft²
2:
2((13)5 + (5)6 + (13)6)
2(65 + 30 + 78)
2(173)
346 mm²
3:
2((20)4 + (4)15 + (20)15)
2(80 + 60 + 300)
2(440)
880 in²