Answer:
1/1560
Step-by-step explanation:
The chance of you winning is 1/40, since there are 40 students and you are one of those students. Since, you cannot win again once you win once, you are eliminated. This leaves us with 39 people left. The chances of your friend being chosen out of the 39 people left is 1/39. Now you must multiply 1/40 and 1/39. After multiplying, you get 1/1560.
and 
. So we have a remainder of
and 
. Subtracting this from the previous remainder gives a new remainder
and 
. Subtracting this from the previous remainder gives a new one of
and we're done since 2 does not divide 
. So we have
To find the circumference of a semi-circle, it would be 1/2<span> π × d. So, pi (3.14) times the diameter, 5 would be 15.7, but then we would need to multiply it by 1/2 to get the circumference for half the circle, and that will get you 7.85. Now you can add all the lengths now. 7.85 + 7 + 5 + 7 = 26.85. Hope this helps! Let me know if you still don't get it. <3</span>
The answer is r = p/2n - x/n
