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: if x gets 25 % more than y and y gets 20 % more than z, the share of z out of rs. 1110 will be :
Options: a. rs. 300, b. rs. 200, c. rs. 240, d. rs. 350, e. none of these
[EX A]: a

[EX Q]: Problem: a sum of money at simple interest amounts to $ 645 in 3 years and to $ 690 in 4 years. the sum is :
Options: a. $ 153, b. $ 510, c. $ 598, d. $ 549, e. $ 675
[EX A]: b

[EX Q]: Problem: x starts a business with rs. 45000. y joins in the business after 3 months with rs. 30000. what will be the ratio in which they should share the profit at the end of the year ?
Options: a. 1: 2, b. 2: 1, c. 1: 3, d. 3: 1, e. 1: 1
[EX A]:
b