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: 18.05 ã — 0.001 = ?
Options: a. 0.1805, b. 0.01805, c. 1.805, d. 0.001805, e. none of these

Answer: b


Question: Problem: a train covers a distance of 100 km in 1 hour. if its speed is decreased by 15 km / hr, the time taken by the car to cover the same distance will be ?
Options: a. 1 hr, b. 1 hr 10 min, c. 50 min, d. 1 hr 30 min, e. 1 hr 45 min

Answer: b


Question: Problem: joe ’ s average ( arithmetic mean ) test score across 4 equally weighted tests was 45. he was allowed to drop his lowest score. after doing so, his average test score improved to 50. what is the lowest test score that was dropped ?
Options: a. 20, b. 30, c. 55, d. 65, e. 80

Answer:
b