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.
--------
Question: Problem: the denominator of a fraction is 7 greater than the numerator. if the numerator and the denominator are increased by 4, the resulting fraction is equal to 5 " 6. what is the value of the original fraction ?
Options: a. 23 / 30, b. 25 / 32, c. 31 / 38, d. 37 / 44, e. 47 / 54

Answer: c

Question: Problem: the average age of a family of 5 members is 20 years. if the age of the youngest member be 10 years then what was the average age of the family at the time of the birth of the youngest member ?
Options: a. 13.5, b. 14, c. 15, d. 12.5, e. none

Answer: d

Question: Problem: in a new housing development, trees are to be planted along the sidewalk of a certain street. each tree takes up one square foot of sidewalk space, and there are to be 9 feet between each tree. how many trees can be planted if the road is 151 feet long ?
Options: a. 8, b. 9, c. 10, d. 11, e. 16

Answer:
e