as is customary with this quantity of questions, I will only provide answers and not detailed solutions
so the general thing you need to find the solutions
mode=most repeated number
mean=average
probabilty=(desired outcomes)/(total possible outcomes)
permutations (how many ways can you pick...) if you have the question
'how many ways can you order 3 blocks' you do
3 possible for first slot
2 possible for second since 1 was in firrst slot
1 possible for last so
number is 3 times 2 times 1=6 ways
so if you did have one like
'if you can pick 3 blocks from a selection of 10 blocks, how many ways can you pickthem (order counts'
so 10 in first slot
9 in second
8 in third so
10 times 9 times 8=720 ways
1. first or 11
2. third or 9/20
3. first or 2/15
4. second or 36
5. first or 1680
6. fourth 8.625
7. fourth or no mode
8. third or 2008