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: a and b started a business in partnership investing rs. 20,000 and rs. 15,000 respectively. after 6 months, c joined them with rs. 20,000. whatwill be b ' s share in total profit of rs. 15,000 earned at the end of 2 years from the startingof the business ?
Options: a. s. 5,000, b. s. 4,500, c. s. 5,700, d. s. 6,500, e. s. 7,500
b

Problem: there are 27 different 3 - digit integers that can be formed using only the digits 3, 4 and 5. if all 27 of the integers were listed, what would their sum be ?
Options: a. 11,888, b. 11,988, c. 12,088, d. 12,188, e. 12,288
b

Problem: the average age of students of a class is 15.8 years. the average age of boys in the class is 16.4 years and that of the girls is 15.7 years. the ration of the number of boys to the number of girls in the class is ?
Options: a. 1: 6, b. 2: 3, c. 2: 5, d. 2: 1, e. 2: 4
a