I kind of have the same problem with these things.
There are more complicated problems that bug me. Those seem quite simple.
For the first one, I think you have 6 * 8. Becase for each one of the 6 men, you have 8 possible women to create a couple, these means 6 * 8.
I don't understand the second problem. You didn't mention any way of picking.
For the third problem, it's probably permutations since order MATTERS here. Why does order matter? Well, if you'd make the team Michael, George and John, you could make George the leader, John the scribe and Michael the timekeeper, or you could make John the leader, Michael the scribe and George the time keeper and so on. Thus, oder matters. The team George/John/Michael is not the same as John/Michael/George.
If you would have to make a team of people where their roles woudn't have mattered, then the team formed by the persons A, B, C would've been the same as the team A, C, B etc. so you would have to use combinations.
For the fourth problem, order matters again as you can form the word "tue" as well as the word "teu" or "etu" etc. using the letters t, u and e. So, again, here is the case of permutations since order matters.