3
$\begingroup$

what is the formula to calculate the probabilities of getting 2 heads or more in 3 coin toss ? i've seen a lot of solution but almost all of them were using method of listing all of possible combination like HHT,HTH,etc

what i am trying to ask is the formula and/or method to calculate this using a formula and no need to list all of the possible combination.

listing 3 coin toss combination is easy(8 possible combination),but suppose i change the coins to dice or say 20-side dice. that would take a long time to list all the possible combination.

  • 1
    In a number of important cases, there are relatively simple formulas that will do the counting for you, so you do not need to make a list and then count. However, it is a good idea to do the counting yourself in a number of "small" cases, so that you will know what is going on.2012-12-29
  • 0
    http://math.stackexchange.com/questions/151810/probability-of-3-heads-in-10-coin-flips2016-09-30

4 Answers 4