The time between failures for an electrical appliance is exponentially distributed with a mean of $25$ months. What is the probability that the next failure will not occur before $30$ months have elapsed?

Multiple Choice

in excess of $\mathrm{.}6$

in excess of $\mathrm{.}4$ but not in excess of $\mathrm{.}6$

in excess of $\mathrm{.}2$ but not in excess of $\mathrm{.}3$

in excess of $\mathrm{.}3$ but not in excess of $\mathrm{.}4$

not in excess of $\mathrm{.}2$