9/18 or 50% if you toss the coin because when you toss 1 coin you get a 1/2 chance of getting tails. Do that nine times and you get 9/18
17 Answer: 205
<u>Step-by-step explanation:</u>


18 Answer: 1968
<u>Step-by-step explanation:</u>


19 Answer: -116
<u>Step-by-step explanation:</u>

Answer:
53
Step-by-step explanation:
70-17= 53