Need help with this ASAP

Question

A biased coin with  Pr(T)=0.6 is tossed 85 times. Compute the expected number of times a head comes up. 

 

Finals is here and I have no idea how to get an answer!

Answer 1

Pr(T) would be the probability of getting tails.

The probability of getting heads OR tails is 100%, or 1.0, so Pr(H) = 1.0 - 0.6 = 0.4.

That's 4 out of 10.

 

How many heads out of 85 tosses?

0.4 * 85 = 34