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: the cost price of a radio is rs. 1800 and it was sold for rs. 1430, find the loss % ?
Options: a. 18 %, b. 20.5 %, c. 30 %, d. 45 %, e. 12 %
[EX A]: b

[EX Q]: Problem: sheila works 8 hours per day on monday, wednesday and friday, and 6 hours per day on tuesday and thursday. she does not work on saturday and sunday. she earns $ 360 per week. how much does she earn in dollars per hour ?
Options: a. 11, b. 10, c. 9, d. 8, e. 7
[EX A]: b

[EX Q]: Problem: a woman complete a journey in 20 hours. she travels first half of the journey at the rate of 21 km / hr and second half at the rate of 24 km / hr. find the total journey in km.
Options: a. 334 km., b. 216 km., c. 314 km., d. 448 km., e. 544 km.
[EX A]:
d