Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.

[Q]: Problem: heinz produces tomato puree by boiling tomato juice. the tomato puree has only 20 % water while the tomato juice has 90 % water. how many liters of tomato puree will be obtained from 25 litres of tomato juice ?
Options: a. 2.8 liters., b. 3.125 liters., c. 8.5 liters., d. 2.6 liters., e. 2.1 liters.
[A]: b


[Q]: Problem: what will be the percentage increase in the area of the cube ' s surface if each of the cube ' s edges grows by 40 % ?
Options: a. 95 %, b. 90 %, c. 85 %, d. 96 %, e. 25 %
[A]: d


[Q]: Problem: a sum of money at simple interest amounts to rs. 815 in 3 years and to rs. 878 in 4 years. the sum is :
Options: a. 500, b. 698, c. 626, d. 910, e. none
[A]:
c