numb of flights before failure / prob nobody fills up

[someguy54]

I have two questions...

1) A plane engine stalls 1 in 50 times. When the first critical item fails, the plane crashes. On average how many times can the plane fly before the first critical item fails?

Would the answer just be 25?

2) Someone fills their car up at a gas station once every 3 minutes. What is the probability that no one fills up between 11:30 and 11:35?

I have no clue where to start on this one.

Thanks!

 

[tkhunny]

The first question makes no sense. Is that the WHOLE problem statement?

On the second: You have 1 customer / 3 minutes. For a 5-minute period, that's 1.6666666 customer. Do you have a Poisson Distribution?