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: for the past n days, the average ( arithmetic mean ) daily production at a company was 50 units. if today ' s production of 110 units raises the average to 55 units per day, what is the value of n ?
Options: a. 9, b. 11, c. 13, d. 15, e. 17
b

Problem: a textile manufacturing firm employees 100 looms. it makes fabrics for a branded company. the aggregate sales value of the output of the 100 looms is rs 5, 00,000 and the monthly manufacturing expenses is rs 1, 50,000. assume that each loom contributes equally to the sales and manufacturing expenses are evenly spread over the number of looms. monthly establishment charges are rs 75000. if one loom breaks down and remains idle for one month, the decrease in profit is :
Options: a. 13000, b. 7000, c. 10000, d. 3500, e. none of these
d

Problem: if ( x + 3 ) ^ 2 / ( 2 x + 15 ) = 3, then the difference between the two possible values of x is :
Options: a. 8, b. 10, c. 12, d. 14, e. 16

c