The answer with the work has been provided previously.
Answer:
Step-by-step explanation:
The probability that a mosquito lands on your neck per second is 0.5
The chance of it biting once it lands is 0.2
The likelihood that it does not bite after landing is 0.8
Therefore, the probability of a bite in one second is 
This translates to a 1/100 likelihood of being bitten in just one second
Over the course of 100 seconds, the expected number of bites is 
The anticipated interval between bites is 100