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
| $x$ | $c$ | $2 c$ | $3 c$ | $4 c$ | $5 c$ | $6 c$ |
| $f$ | 2 | 1 | 1 | 1 | 1 | 1 |
is 160 , then the value of $c \in N$ is
(1) 7
(2) 8
(3) 5
(4) 6