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: In a class of 40 students, 10 did not opt for math. 15 did not opt for science and 2 did not opt for either. How many students of the class opted for both math and science?

Option A: 13

Option B: 15

Option C: 7

Option D: 17

Option E: 18

SOLUTION: Option C

PROBLEM: Question: Two pipes A and B can fill a tank in 15 min and 20 min respectively. Both the pipes are opened together but after 4 min, pipe A is turned off. What is the total time required to fill the tank?

Option A: 14 min 19 sec

Option B: 14 min 42 sec

Option C: 14 min 20 sec

Option D: 14 min 40 sec

Option E: 14 min 10 sec

SOLUTION: Option D

PROBLEM: Question: What is the length of a bridge (in meters), which a train 156 meters long and travelling at 45 km/h can cross in 30 seconds?

Option A: 203

Option B: 211

Option C: 219

Option D: 227

Option E: 235

SOLUTION:
Option C