Question

Jenna flips two pennies 105 times how many times can she expect those coins to come up heads

Answer 1

The more observations you make the closer and closer the experimental probability will approach the theoretical probability.  In this case the theoretical probability is:

P(HH)=(1/2)(1/2)=1/4

So in 105 trials one would expect to get two heads:

105(1/4)=26.25 times.