Determining the time intervals

[estado3]

Homework Statement

Assuming that the random time to failure of a relay is exponentially distributed with a failure rate lambda of 2 x 10^-7 per hour, determin ethe time intervals between failures(years) which have 99%, 95%, 50%, 1%, and 0.1% probabilities of being exceeded

Homework Equations

Reliability function 1- the cumulative distribution function

The Attempt at a Solution

putting in the values of lambda 2 X 10^-7 and hours per year of (24 x 31 x 12) my value is way off the mark for 99% which is 5.7, incidentally 95%, 50%, 1%, and 0.1% are 29.3, 394.6, 2628.5, and 3942.8

 

[EnumaElish]

What is your value, and how did you arrive at it?