**Step-by-step explanation: Hi!**

**well, the only case where someone wins is if two of them chose the same thing, and the other chose one of the two remaining possibilities.**

**an useful way of starting this is calculated al the possible combinations of rock, paper and scissors.**

**we have 3 persons and 3 options, ence the total number of permutations is 3*3*3 = 27**

** So, the cases where none wins are:**

**1) the 3 chose the same thing: there are 3 combinations here, one for each option**

**2) the 3 chose a different thing: here you think, the first one has 3 possibilities, then the second one must choose a different option, so has 2, and the third one only has 1 remaining option. so you have 6 combinations.**

**so there are 6 + 3 = 9 combinations where no one wins, if we want to se the probability, we compute 9/27 = 1/3 = 0.33%.**

**But the problem ask for it to happen 4 times in a row, so you will have 0.33*0.33*0.33*0.33 = 1/81 chances that this happens**