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.

Question: On flipping 3 coins together what is the outcomes for at least four tail?

 Option A: 1/7

 Option B: 0

 Option C: 1

 Option D: 4/13

 Option E: 5/13
Option B

Question: 10 3/4 + 7 2/17 - 9 1/15=?

 Option A: 7 719/1020

 Option B: 9 817/1020

 Option C: 9 719/1020

 Option D: 8 817/1020

 Option E: None of them
Option D

Question: Total 60 cows 20 cow gives each 2 liter milk 20 cow gives each 3/4 liter milk 20 cow gives each 1/4 liter milk this is split into 3 son per each 20 cows & 20 liter milk how?

 Option A: 20

 Option B: 10

 Option C: 15

 Option D: 16

 Option E: 18

Option A