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.
--------
Question: Problem: a student took 5 papers in an examination, where the full marks were the same for each paper. his marks in these papers were in the proportion of 6: 7: 8: 9: 10. in all papers together, the candidate obtained 60 % of the total marks then, the number of papers in which he got more than 50 % marks is
Options: a. 1, b. 3, c. 4, d. 5, e. 7

Answer: c


Question: Problem: a and b started a business investing rs. 80,000 and rs 20,000 respectively. in what ratio the profit earned after 2 years be divided between a and b respectively ?
Options: a. 4: 1, b. 3: 2, c. 18: 20, d. 18: 4, e. 17: 4

Answer: a


Question: Problem: at what rate percent on simple interest will rs. 750 amount to rs. 900 in 5 years ?
Options: a. 6, b. 5, c. 4, d. 78, e. 2

Answer:
c