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 average monthly income of P and Q is Rs. 5050. The average monthly income of Q and R is Rs. 6250 and the average monthly income of P and R is Rs. 5200. The monthly income of P is:

 Option A: 3500

 Option B: 4000

 Option C: 4050

 Option D: 5000

 Option E: 6000
answer:
Option B


question:
Question: A is twice as fast as B. If B alone can do a piece of work in 18 days, in what time can A and B together complete the work?

 Option A: 10

 Option B: 16

 Option C: 18

 Option D: 6

 Option E: 12
answer:
Option D


question:
Question: What is the average of 1/2, 1/5 and 3/10?

 Option A: 1/5

 Option B: 3/10

 Option C: 2/5

 Option D: 1/3

 Option E: 6/5
answer:

Option D