The answer is c because you have the right mathmatics
The surface is the sun of all the sides. With the information provide I can only work out the volume, which is 420cm^3
B and c I believe ..........
Sorry didn't know how to write the answer so I just took a screen shot of my answer for you!
Answer:
for b-10 the b=5 and b+10 b=4
Step-by-step explanation: