For this question, I originally solved it (0.2)^3 * (0.8)^2 and then multiplied that by how many ways we can make 3 (0.2) and 2 (0.8) using combinatorics which was 5!/(3!2!) and that gave me 10. So my answer was approximately 5%.
Here in the solution video, Greg just manually does it and says the ways to make this (3 (0.2) and 2 (0.8)) was 3.
Can someone help me understand why my approach doesn’t work?