instruction:
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: when positive integer n is divided by 7, the remainder is 1. when n is divided by 11, the remainder is 5. what is the smallest positive integer k such that k + n is a multiple of 77 ?
Options: a. 2, b. 4, c. 6, d. 8, e. 10
answer:
c


question:
Problem: a train running at the speed of 20 km / hr crosses a post in 10 seconds. what is the length of the train ?
Options: a. 150, b. 250, c. 415, d. 200, e. 312
answer:
d


question:
Problem: one type of liquid contains 10 % of water and the second type of liquid contains 15 % of water. a glass is filled with 5 parts of 1 st liquid and 2 parts of 2 nd liquid. the percentage of water in the new mixture in the glass is ?
Options: a. 5.6 %, b. 11.4 %, c. 15.6 %, d. 21.3 %, e. 18.9 %
answer:

b