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: The difference between simple and compound interests compounded annually on a certain sum of money for 2 years at 4% per annum is Re. 1. The sum (in Rs.) is?

 Option A: 625

 Option B: 827

 Option C: 657

 Option D: 726

 Option E: 634
answer:
Option A


question:
Question: Calculate the sum of first 60 natural numbers.

 Option A: 1839

 Option B: 2830

 Option C: 1830

 Option D: 1831

 Option E: 1835
answer:
Option C


question:
Question: Lamp A flashes every 6 seconds, Lamp B flashes every 8 seconds, Lamp C flashes every 10 seconds. At a certain instant of time all three lamps flash simultaneously. During the period of 4 minutes after that how many times will exactly two lamps flash? (Please include any flash of exactly two lights which occurs at the 4 minute mark.)

 Option A: 16

 Option B: 17

 Option C: 18

 Option D: 19

 Option E: 20
answer:

Option C