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:. 005 / ? =. 01
Options: a.. 5, b.. 05, c.. 005, d.. 0005, e. none of them
[EX A]: a

[EX Q]: Problem: for 2 consecutive yrs, my incomes are in the ratio of 4: 7 and expenses in the ratio of 3: 5. if my income in the 2 nd yr is rs. 42000 & my expenses in the first yr in rs. 23000, my total savings for the two - year is
Options: a. s. 8000, b. s. 9000, c. s. 9900, d. s. 9990, e. s. 10000
[EX A]: a

[EX Q]: Problem: the average weight of a group of boys is 30 kg. after a boy of weight 45 kg joins the group, the average weight of the group goes up by 1 kg. find the number of boys in the group originally ?
Options: a. 14, b. 15, c. 16, d. 17, e. 18
[EX A]:
a