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: A lady bought five books namely A,B,C,D,E to distribute her 7 friends. How many ways she can distribute books?

 Option A: 7^3

 Option B: 7^4

 Option C: 7^5

 Option D: 7^6

 Option E: 7^2
Option C

Question: A contractor undertakes to built a walls in 50 days. He employs 60 peoples for the same. However after 25 days he finds that only 40% of the work is complete. How many more man need to be employed to complete the work in time?

 Option A: 25

 Option B: 90

 Option C: 35

 Option D: 20

 Option E: None of these
Option B

Question: The unit digit in the product (722 * 774 * 889 * 223) is:

 Option A: 2

 Option B: 7

 Option C: 6

 Option D: 8

 Option E: 1

Option C