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.

[EX Q]: Question: One water pump can fill half of a certain empty tank in 7 hours. Another pump can fill half of the same tank in 7.5 hours. Working together, how long will it take these two pumps to fill the entire tank?

 Option A: 7 7/13

 Option B: 1 5/8

 Option C: 3 1/4

 Option D: 7 7/29

 Option E: 3 1/2
[EX A]: Option D

[EX Q]: Question: For an employee to qualify for early retirement at a certain company, the sum of the employee’s age and years of service must be at least 72, If Sue was K years old when she was hired by the company, what is the minimum age at which she could possibly qualify for early retirement.

 Option A: K+36

 Option B: 2K+36

 Option C: (72+K

 Option D: (72-K

 Option E: 2(72-K
[EX A]: Option C

[EX Q]: Question: Suppose you have access to a large vat of distilled water, several gallons large. You have two precise measuring pipettes, one to measure exactly 1/5 of an ounce and one to measure exactly 1/6 of an ounce. You can pour precisely measured amounts into a beaker, which initially is empty. You can use either pipette to remove distilled water from the vat or from the beaker and use either pipette to dispense water into either of those receptacles, but you cannot use either pipette to take any quantity of distilled water other than the amount for which it is designed. Which of the following represents, in ounces, a precise amount of distilled water you can transfer from the vat to the beaker?
I. 1/6
II. 1/7
III. 1/12

 Option A: I only

 Option B: III only

 Option C: 1/30 and 11/30

 Option D: II and III only

 Option E: I, II, and III
[EX A]:
Option C