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: a 270 metres long bullet train running at the speed of 120 kmph crosses another bullet train running in opposite direction at the speed of 80 kmph in 9 seconds. what is the length of the other bullet train ?
Options: a. 226, b. 230, c. 430, d. 310, e. 260
[EX A]: b

[EX Q]: Problem: a merchant marks his goods up by 30 % and then offers a discount of 10 % on the marked price. what % profit does the merchant make after the discount ?
Options: a. 17 %, b. 25 %, c. 69 %, d. 31 %, e. 19 %
[EX A]: a

[EX Q]: Problem: sue ' s trail mix is 30 % nuts and 70 % dried fruit. jane ' s trail mix is 60 % nuts and 40 % chocolate chips. if the combined mixture of sue and jane ' s trails mix contains 40 % nuts, what percent of the combined mixture is dried fruit ?
Options: a. 16.7 %, b. 23.33 %, c. 25 %, d. 33.3 %, e. 46.7 %
[EX A]:
e