Answer:
Option A is correct.
Step-by-step explanation:
We have been given that the there are 6 medals which are to be awarded from first place through 6th place
So, there will be arrangement of the medals among 6 medals so, it will be 6!

Therefore, Option A is correct that is permutation; number of ways 720.
Answer:
B
Step-by-step explanation:
Answer: 12 and 8
Step-by-step explanation:
Their difference is four while others aren't.
Answer:
40078-18537=21541
Step-by-step explanation: