TASK DEFINITION: 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: Problem: two trains, one from howrah to patna and the other from patna to howrah, start simultaneously. after they meet, the trains reach their destinations after 10 hours and 8 hours respectively. the ratio of their speeds is
Options: a. 4: 9, b. 4: 3, c. 4: 12, d. 4: 8, e. 4: 5

SOLUTION: e

PROBLEM: Problem: a 270 metres long bullet train running at the speed of 120 kmph crosses another bullet train running in opposite direction at the speed of 80 kmph in 9 seconds. what is the length of the other bullet train ?
Options: a. 226, b. 230, c. 430, d. 310, e. 260

SOLUTION: b

PROBLEM: Problem: set a { 3, 3,3, 4,5, 5,5 } has a standard deviation of 1. what will the standard deviation be if every number in the set is multiplied by 5 ?
Options: a. a. 1, b. b. 2, c. c. 4, d. d. 8, e. e. 5

SOLUTION:
e