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: if 5 a = 3125, then the value of 5 ( a - 3 ) is :
Options: a. 25, b. 125, c. 625, d. 1625, e. none of these
[A]: a


[Q]: Problem: what is the rate percent when the simple interest on rs. 810 amount to rs. 155 in 4 years ?
Options: a. 4.78, b. 4.68, c. 4.58, d. 4.48, e. 4.38
[A]: a


[Q]: Problem: a car drives 60 miles on local roads at 20 mph, and 195 miles on the highway at 65 mph, what is the average speed of the entire trip ?
Options: a. 36 mph, b. 40 mph, c. 44 mph, d. 43 mph, e. 58 mph
[A]:
d