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.

[EX 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 %
[EX A]: d

[EX Q]: Problem: a couple spent $ 211.20 in total while dining out and paid this amount using a credit card. the $ 211.20 figure included a 20 percent tip which was paid on top of the price which already included a sales tax of 10 percent on top of the price of the food. what was the actual price of the food before tax and tip ?
Options: a. $ 120, b. $ 140, c. $ 150, d. $ 160, e. $ 180
[EX A]: d

[EX Q]: Problem: a train running at the speed of 60 km / hr crosses a pole in 6 sec. what is the length of the train ?
Options: a. 356, b. 278, c. 127, d. 100, e. 150
[EX A]:
d