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.
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Question: Problem: a worker is paid a regular rate of rs. 30 for completing a survey. the worker completes 100 surveys per week. for any survey involving the use of her cellphone, she is paid at a rate of that is 20 % higher than her regular rate. if she completed 50 surveys involving the use of her cellphone, how much did she get that week ?
Options: a. 2200, b. 1100, c. 2500, d. 2800, e. 3300

Answer: e


Question: Problem: a mixture of 70 litres of milk and water contains 10 % water. how many litres of water should be added to the mixture so that the mixture contains 12 1 / 2 % water ?
Options: a. 2, b. 8, c. 6, d. 3, e. 4

Answer: a


Question: Problem: the average mark of the students of a class in a particular exam is 80. if 8 students whose average mark in that exam is 20 are excluded, the average mark of the remaining will be 90. find the number of students who wrote the exam.
Options: a. 15, b. 25, c. 35, d. 45, e. 56

Answer:
e