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: In an electric circuit, two resistors with resistances x and y are connected in parallel. If R is the combined resistance of these two resistors, then the reciprocal of R is equal to the sum of the reciprocals of x and y. What is R if x is 5 Ohms and y is 7 Ohms?

 Option A: 3/5

 Option B: 1/7

 Option C: 12/35

 Option D: 31/12

 Option E: 35/12
answer:
Option E


question:
Question: A wooden box of dimensions 8 m x 7 m x 6 m is to carry rectangularboxes of dimensions 4 cm x 7 cm x 6 cm. The maximum number ofboxes that can be carried in the wooden box, is

 Option A: 9800000

 Option B: 1000000

 Option C: 7500000

 Option D: 2000000

 Option E: None of these
answer:
Option D


question:
Question: A certain quantity of 40% solution is replaced with 25% solution such that the new concentration is 35%. What is the fraction of the solution that was replaced?

 Option A: 1/4

 Option B: 1/3

 Option C: 1/2

 Option D: 2/3

 Option E: 3/4
answer:

Option B