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.

Problem: the price of a book is increased from $ 300 to $ 390. what is the % of increase in its price ?
Options: a. 10 %, b. 20 %, c. 30 %, d. 35 %, e. 45 %
c

Problem: a train which has 430 m long, is running 45 kmph. in what time will it cross a person moving at 9 kmph in same direction ?
Options: a. 56 sec, b. 43 sec, c. 36 sec, d. 29 sec., e. 19 sec.
b

Problem: rs. 1010 / - distributed among a, b and c such that on decreasing their shares by rs. 25, rs. 10 and rs. 15 respectively, the balance money would be divided among them in the ratio 3: 2: 5. then, c ’ s share is: ?
Options: a. rs. 485, b. rs. 495 / -, c. rs. 575, d. rs. 685, e. rs. 592

b