$cov (x,y)$ if $\Sigma x = 55\: \Sigma y = 82\: \Sigma xy = 565\: n=8$ is

$\begin {array} {1 1} (A)\;0.16 & \quad (B)\;0.7 \\ (C)\;7 & \quad (D)\;6 \end {array}$

$cov (x,y) = \large\frac{n \Sigma xy - ( \Sigma x ) ( \Sigma y)}{n^2}$
$= \large\frac{8(565)-(55)(82)}{8 \times 8}$
$= \large\frac{4520-4510}{64}$
$= \large\frac{10}{64}$
$= 0.16$
Ans : (A)