TASK DEFINITION: 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.
PROBLEM: 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%

SOLUTION: Option B

PROBLEM: Question: The probability that a visitor at the mall buys a pack of candy is 30%. If three visitors come to the mall today, what is the probability that exactly two will buy a pack of candy?

 Option A: 343

 Option B: 147

 Option C: 189

 Option D: 063

 Option E: 027

SOLUTION: Option C

PROBLEM: Question: A man rows his boat 85 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?

 Option A: 7 kmph

 Option B: 4 kmph

 Option C: 4 kmph

 Option D: 8 kmph

 Option E: 5 kmph

SOLUTION:
Option D