TASK DEFINITION: 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.
PROBLEM: Question: Evaluate combination
100C98=100!/(98)!(2)!

 Option A: 4950

 Option B: 1510

 Option C: 4170

 Option D: 3170

 Option E: None of these

SOLUTION: Option A

PROBLEM: Question: The original price of a shirt was $20. It was decreased to $15 . What is the percent decrease of the price of this shirt.

 Option A: 25%

 Option B: 35%

 Option C: 45%

 Option D: 55%

 Option E: 65%

SOLUTION: Option A

PROBLEM: Question: A train running at the speed of 60 km/hr crosses a pole in 18 seconds. Find the length of the train.

 Option A: 150

 Option B: 278

 Option C: 179

 Option D: 300

 Option E: 191

SOLUTION:
Option D