What is the length of an edge of a cube whose total surface area is...
MATHEMATICS
WAEC 2008
What is the length of an edge of a cube whose total surface area is X cm2 and whose total surface area is \(\frac{X}{2}\)cm3?
- A. 3
- B. 6
- C. 9
- D. 12
Correct Answer: A. 3
Explanation
Total surface area of cube = 6s2
6s2 = x
s2 = x = \(\frac{x}{6}\).....(1)
volume of a cube = s2 = \(\frac{x}{2}\)
s2 = \(\frac{x}{2}\)......(2)
put(1) into (2)
s(\(\frac{x}{6}\)) = \(\frac{x}{2}\)
s = \(\frac{x}{2} \times \frac{6}{x}\)
= 3cm
Post an Explanation Or Report an Error
If you see any wrong question or answer, please leave a comment below and we'll take a look. If you doubt why the selected answer is correct or need additional more details? Please drop a comment or Contact us directly. Your email address will not be published. Required fields are marked *