The diameter of a circle is 3.5 cm. What is the circumference of the circle ?

Answer: Option A

Radius :
$$\begin{array}{rl}& =\frac{3.5}{2}cm\\ & =\frac{7}{4}cm\end{array}$$
∴ Circumference :
$$\begin{array}{rl}& =\left(2\times \frac{22}{7}\times \frac{7}{4}\right)cm\\ & =11cm\end{array}$$