Originally Posted by

**Gaarleaf** Hi, I was wondering if anyone could help me out with this question:

I really have no idea where to proceed.

Billy enters a shed, and close the door. Inside the shed there are 6 mosquitoes.

One of them carries the Ross River virus.

a) Billy is bitten by a mosquito which he slaps and kills. He is then bitter by another mosquito, and again slaps and kills the offender. Find the probability that Billy was bitten by the mosquito with the virus.

b) (A new situation, still with 6 mosquitoes).

While in the shed, Billy was bitten twice. Calculate the probability that Billy was bitten by the virus carrying mosquito at least once, given that he swiped but missed after feeling each bite.

Any help is much appreciated!