Subject: General Aptitude · Chapter: Area · Exam: 2006 · Marks: · Difficulty:
The minute hand of a clock is 7 cm long. Find the area of the sector made by the minute hand between 7 a.m. and 7.05 a.m.
(a)$11.5 \mathrm{cm}^{2}$
(b)$12.8 \mathrm{cm}^{2}$
(c)$15.4 \mathrm{cm}^{2}$
(d)None of these
Answer
Answer (as printed): B
Explanation
Angle traced by the minute hand in 5 minutes $$=\left(\frac{360}{60} \times 5\right)^{\circ}=30^{\circ} .$$ ∴ Area of the sector $$=\left(\frac{22}{7} \times 7 \times 7 \times \frac{30}{360}\right) \mathrm{cm}^{2}=12.83 \mathrm{cm}^{2} .$$