instruction:
You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.
question:
Question: Look at this series: 8, 43, 11, 41, __, 39, 17, ... What number should fill in the blank?

 Option A: 22

 Option B: 33

 Option C: 14

 Option D: 16

 Option E: 18
answer:
Option C


question:
Question: The population of a certain town increases by 50 percent every 50 years. If the population in 1950 was 810, in what year was the population 160?

 Option A: 1650

 Option B: 1700

 Option C: 1750

 Option D: 1800

 Option E: 1850
answer:
Option C


question:
Question: The speed of a boat in upstream is 60 kmph and the speed of the boat downstream is 80 kmph. Find the speed of the boat in still water and the speed of the stream?

 Option A: 76 kmph

 Option B: 10 kmph

 Option C: 29 kmph

 Option D: 25 kmph

 Option E: 16 kmph
answer:

Option B