Is this correct? or incorrect? volume and surface area of cuboids

Question

Is my homework correct?

volume and surface area of cuboids

https://i.stack.imgur.com/UovRN.png or see below:

Answer 1

Corrections (only 1. a. SA was fully correct):

1. a. $V\!=\!144$ cm$^3$. b. $V\!=\! 240$ mm$^3$, SA = $236$ mm. c. $V\!=\! 120.416$ cm$^3$, SA = $154.62$ cm.
2. $V\!=\!60\cdot 70\cdot 400 - 20\cdot 30\cdot 400\!=\!1440000$ (cm$^3$).
3. $V\!=\!30\cdot 40\cdot 6+12\cdot 8\cdot 30\!=\!10080$ (cm$^3$).

Remember: $\text{cm}\times\text{cm}\times\text{cm}=\text{cm}^3$ and $4 \text{ m}=400 \text{ cm}$.