You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.

[Q]: Question: A and B complete a work in 6 days. A can alone can do it in 10 days. If both can together can do the work in how many days?

 Option A: 7

 Option B: 3.75

 Option C: 2

 Option D: 1

 Option E: 8
[A]: Option B


[Q]: Question: Anthony and Michael sit on the six member board of directors for company X. If the board is to be split up into 2 three-person subcommittees, what percent R of all the possible subcommittees that include Michael also include Anthony?

 Option A:  20%

 Option B:  30%

 Option C:  40%

 Option D:  50%

 Option E:  60%
[A]: Option C


[Q]: Question: 20 throws of a die produces following results
SCORE -- NUMBER OF OCCURRENCES
---1-------------------4
---2-------------------3
---3-------------------5
---4-------------------2
---5-------------------2
---6-------------------4
What is the probability C that one more throw to this series will increase the mean score?

 Option A: 1/6

 Option B: 1/3

 Option C: 1/2

 Option D: 2/3

 Option E: 5/6
[A]:
Option C