Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: · Marks: · Difficulty:
A solid cylinder of base radius 7 cm and height 24 cm is surmounted by a cone of the same radius and same vertical height. A hemisphere surmounts the cylinder at the other end. Surface area of the solid will be
(a)$527 \pi \mathrm{cm}^{2}$
(b)$609 \pi \mathrm{cm}^{2}$
(c)$707 \pi \mathrm{cm}^{2}$
(d)$805 \pi \mathrm{cm}^{2}$
Answer
Answer (as printed): B
Explanation
Surface area of the solid = = Curved surface area of cone + Curved surface area of cylinder + Curved surface area of hemisphere $=\binom{\pi \times 7 \times \sqrt{7^{2}+(24)^{2}}+2 \pi \times 7}{\times 24+2 \pi \times 7 \times 7} \mathrm{cm}^{2}$ $=(175 \pi+336 \pi+98 \pi) \mathrm{cm}^{2}=(609 \pi) \mathrm{cm}^{2}$.