expected value of filtered binomial

Assume a bernoulli random variable with success probability p. In 12 independent trials of the bernoulli I only look at the third, sixth, nineth and twelfth experiment. What is the expected value of the number of successes that I observe at these four occasions?

Since the trials are independent, the expected value is still $p$.
• you mean $4p$ I assume? – user83346 Mar 6 '16 at 9:50
• You wrote "What is the expected value of the number of successes that I observe at these four occasions?", then at each occasion the expected value is $p$. Of course, if you want to know the expected number of success in these four occasion, it is $4p$. – stochazesthai Mar 6 '16 at 9:55