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.

[EX Q]: Question: There are 4 boys and 3 girls seated in a row.Find the probability that all girls are together?

 Option A: 1/6

 Option B: 1/7

 Option C: 2/7

 Option D: 3/7

 Option E: 4/7
[EX A]: Option B

[EX 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
[EX A]: Option B

[EX Q]: Question: A cistern is normally filled in 10 hours but takes two hours longer to fill because of a leak in its bottom. If the cistern is full, the leak will empty it in?

 Option A: 33

 Option B: 88

 Option C: 60

 Option D: 99

 Option E: 11
[EX A]:
Option C