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: find the maximum value of the function f ( x ) = x − 5 if x is a number between - 5 and 13.
Options: a. 6, b. 7, c. 8, d. 9, e. none
answer:
c


question:
Problem: if the price of a certain computer increased 30 percent from b dollars to 351 dollars, then 2 b =
Options: a. 540, b. 570, c. 619, d. 649, e. 700
answer:
a


question:
Problem: 90 kg of an alloy a is mixed with 140 kg of alloy b. if alloy a has lead and tin in the ratio 3: 4 and alloy b has tin and copper in the ratio 2: 5, then the amount of tin in the new alloy is ?
Options: a. 100.6 kg, b. 95.4 kg, c. 117.5 kg, d. 91.4 kg, e. 92 kg
answer:

d