Step-by-step explanation: The sample space are all of the different outcomes an event can lead to. The H and T combinations at the bottom are all of the different outcomes. I think the probability of getting 3 tails for the coins (or TTT) is 1/8. This is because there are 24 total outcomes (HHH, HHT, HTH, HTT, THH, THT, TTH, TTT). There is 3/24 TTTs (also, 1/8 if you count the groups/simplify). Therefore, it is 1/8. Hope this helps!