Probability with counting outcomes

find the probability of flipping exactly two heads on three coins so to figure out this probability a good place to start is just to think about all of the different possible ways that we can flip three coins so we could get we could get all tails tails tails tails we could get tails tails heads we could get tails heads tails we could get tails heads heads we could get heads tails tails we could get heads tails heads we could get heads heads tails and then we could get all heads and we could get all heads over here so they are one two three four five six seven eight possible outcomes eight possible outcomes outcomes now how many of the outcomes involve flipping exactly exactly two heads let's see that's all tails it's one hand one hand this has two heads right there two heads it's one head this is two heads right over there then this is two heads right over here and then this is three heads so that doesn't count so there are three three outcomes three outcomes where we with exactly with exactly exactly exactly two heads so we spelled heads properly two heads so the probability the probability of flipping of exactly exactly two heads in the word exactly is important because if you didn't say exactly then maybe three heads will you flip two heads so we have to say exactly two heads so you don't so you you don't include the situation where you get three heads so the probability of flipping exactly two heads is equal to the three outcomes with two heads divided by the eight possible outcomes or 3/8 so it is equal to 3/8 and we are done