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: In 165 litres of mixtures of milk and water, water is only 28%. The milkman sold 40 litres of this mixture and then he added 30 litres of pure milk and 13 litres of pure water in the remaining mixture. What is the percentage of water in the final mixture?

 Option A: 29.35%

 Option B: 28. 57%

 Option C: 24. 57%

 Option D: 27. 75%

 Option E: 26. 57%
Option B

Question: The average marks of a class of 35 students is 45 and that of another class of 55 students is 65. Find the average marks of all the students?

 Option A: 52.6

 Option B: 52.4

 Option C: 52.1

 Option D: 57

 Option E: 52.9
Option D

Question: If b is an integer, what is the greatest possible value for b that would still make the following statement true: 11*10^b < 1/10 ?

 Option A:  –4

 Option B:  –3

 Option C:  –2

 Option D:  –1

 Option E:  0

Option B