Sept 2008 Q6

Hello
I am confused as CDF of exp uses \lambda =1/\lambda whereas calculating a certain probability, only \lambda is used as mean.
Here, time until next claim arises follows Exp(2).
In i), no claim made in next one-day period is given by e^((-1/2)*1)
But in iii), P(\sum X>45) when n=30 and
Exp(2)~ N(30*2,30*2^2) is used.
Why did we not use 1/2 instead of 2 in iii) but 1/2 in i)?

 

I see,I need to read the question carefully.
Thank you!