The volume of a cone of height 9cm is 1848cm3. Find its radius. [Take π...
MATHEMATICS
WAEC 1992
The volume of a cone of height 9cm is 1848cm3. Find its radius. [Take π = 22/7]
- A. 7cm
- B. 14cm
- C. 28cm
- D. 98cm
Correct Answer: B. 14cm
Explanation
1/3 πr\(^2\) x 9 = 1848
3 x πr2 = 1848 r2 = 1848/3 x 7/22 r = 14
\(\text{Volume of a cone} = \frac{1}{3} \pi r^2 h\)
\(\frac{1}{3} \times \frac{22}{7} \times r^2 \times 9 = 1848\)
\(r^2 = \frac{1848 \times 7}{22 \times 3}\)
\(r^2 = 196 \therefore r = 14cm\)
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 Your email address will not be published.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 *