Subject: General Aptitude · Chapter: Area · Exam: · Marks: · Difficulty:
The ratio of circumference and diameter of a circle is 22 : 7. If the circumference be $1 \frac{4}{7} \mathrm{m}$. then the radius of the circle is [SSC-CHSL (10+2) Exam, 2015]
(a)$\frac{1}{3} \mathrm{m}$
(b)$\frac{1}{2} \mathrm{m}$
(c)$\frac{1}{4} \mathrm{m}$
(d)1m
Answer
Answer (as printed): C
Explanation
Given: $$\begin{aligned} & \Rightarrow \frac{\text { Circumference of circle }}{\text { Diameter of circle }}=\frac{22}{7} \\ & \Rightarrow \frac{\text { Circumference of circle }}{\text { Twice of radius }}=\frac{22}{7} \\ & \Rightarrow \frac{1 \frac{4}{7}}{2 r}=\frac{22}{7} \\ & \Rightarrow \frac{11}{2 r}=\frac{22}{7} \\ & \Rightarrow \frac{11}{14 r}=\frac{22}{7} \\ & \Rightarrow 14 r \times 22=11 \times 7 \\ & \Rightarrow r=\frac{11 \times 7}{14 \times 22}=\frac{1}{4} \mathrm{m} \end{aligned}$$