#1 There is no area of a cube. There is only a volume.
#2 The formula is

where s is the side.
Substitute 729 in V since that is the volume.

Take the cube root and you will get
9.
So the formula is
and the side is 9.
C is 23 because if you get all rhe numbers and measure thats your answer. I think i might be wrong. if I am then sorry
Okay. Handle 500-100 first. That brings it to 3{5[10+5(400)+399]}. Next, Handle 5(400). That brings you to 3{5{10+2,000+399]}. Then handle all the addition. That leads to 3[5(2,409)]. Next, configure 5(2409). That leads to 3(12045). Then do that one which ends as 36,135 for a final answer.
Since the ratio is 2/5 then for 25 (which is five 5s) there will be 2 × 5 which is 10
Answer: there are 10 bluemuffins