Use a tree diagram.
1. at most two coins come up heads
2. at least two coins come up heads
3. no more than three coins come up tails.© BrainMass Inc. brainmass.com September 24, 2018, 1:26 pm ad1c9bdddf - https://brainmass.com/math/probability/probability-sample-space-probabilities-201196
When 4 coins are tossed, there are 16 possibilities. The sample space is:
The tree diagram would look like this (draw in the arrows yourself):
[see excel file]
First Coin: Second Coin: Third Coin: Fourth ...
The expert makes sample spaces to find the probability.