| $x$ | $c$ | $2 c$ | $3 c$ | $4 c$ | $5 c$ | $6 c$ |
| $f$ | 2 | 1 | 1 | 1 | 1 | 1 |
Q68. $\lim _ { x \rightarrow 0 } \frac { e - ( 1 + 2 x ) ^ { \frac { 1 } { 2 x } } } { x }$ is equal to\\
(1) 0\\
(2) $\frac { - 2 } { e }$\\
(3) e\\
(4) $e - e ^ { 2 }$
Q69.\\
If the variance of the frequency distribution
\begin{center}
\begin{tabular}{ | c | c | c | c | c | c | c | }
\hline
$x$ & $c$ & $2 c$ & $3 c$ & $4 c$ & $5 c$ & $6 c$ \\
\hline
$f$ & 2 & 1 & 1 & 1 & 1 & 1 \\
\hline
\end{tabular}
\end{center}
is 160 , then the value of $c \in N$ is\\
(1) 7\\
(2) 8\\
(3) 5\\
(4) 6