Every number will have only 3 digits. In the ones place, there are 5 choices. For every choice of digit made in the ones place, there are 8 possible choices for the hundreds place (you can choose from 1-9, omitting whatever is used in the ones place), and there are 8 possible choices for the tens place (you can choose from 0-9, omitting whatever has already been used elsewhere).
So there are

such numbers.
Answer:
1)A
2)B
3)A
4)C
5)D
Step-by-step explanation:
15x+5y+6
It can be simplified further if there is an amount this is equal to.
Answer:
60º
Step-by-step explanation:
NXO = MXO - MXN
NXO = 110 - 50
NXO = 60