Discussion
Baskin n Robbin’s biggest ice-cream cardboard cone has height of 24 cm and slant height of 25cm. One sheet of cardboard makes 8 such cones. What is area of the sheet?
Answer: A
A cone's lateral surface is what the cardboard has to supply, so find the radius first.
\[ r = \sqrt{l^{2} - h^{2}} = \sqrt{25^{2} - 24^{2}} = \sqrt{625 - 576} = \sqrt{49} = 7 \text{ cm} \]
\[ \text{CSA} = \pi r l = \frac{22}{7} \times 7 \times 25 = 550 \text{ cm}^{2} \]
\[ \text{sheet area} = 8 \times 550 = 4400 \text{ cm}^{2} \]
A cone rolled from a sheet has no base, so only the curved surface counts - adding \( \pi r^{2} \) would overstate each cone by 154 cm².
No comment is present. Be the first to comment.
Loading…
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development