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.

Q: Question: In a photography exhibition, some photographs were taken by Octavia the photographer, and some photographs were framed by Jack the framer. Jack had framed 24 photographs taken by Octavia, and 12 photographs taken by other photographers. If 36 of the photographs in the exhibition were taken by Octavia, how many photographs were either framed by Jack or taken by Octavia?

 Option A: 36

 Option B: 48

 Option C: 72

 Option D: 96

 Option E: 108

A: Option B
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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

A: Option D
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Q: Question: there are 5 envelope and 5 letters placed at random. what is the probability that no single letter is placed in the right envelope

 Option A: 117/120

 Option B: 118/120

 Option C: 119/120

 Option D: 116/120

 Option E: 115/120

A:
Option C
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