The answer is 90,000. Just remember 5 or above, give it a shove, and for or below let it go. Because 85 has a five at the end you push it up to 90. Same thing with 85,000 or 85,001. You shove it to 90. If it was 84,000 or 84,999 you would let it go to 80,000. Hope that helped!
A. 1/10000 because it is a 1/100 chance for each. b. 1/100 because there are 10,000 options and 100 of them are the same options. Simplify for the answer.