Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.

Problem: 10 ^ ( 600 ) a 10 ^ ( 580 ) = ?
Options: a. 10 ^ 10, b. 10 ^ 20, c. 10 ^ 22, d. 10 ^ 23, e. 10 ^ 24
b

Problem: a man traveled from the village to the post - office at the rate of 25 kmph and walked back at the rate of 4 kmph. if the whole journey took 5 hours 48 minutes, find the distance of the post - office from the village ?
Options: a. 70 m, b. 80 km, c. 20 km, d. 10 km, e. 73 km
c

Problem: a pet store holds cats and dogs. if the difference between the number of cats and the number of dogs is 7. what could be the ratio of cats to dogs in the pet store ?
Options: a. 1: 3, b. 1: 4, c. 28: 35, d. 2: 5, e. 4: 6
c