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: at garage sale, all of the prices of the items sold were different. if the price of a radio sold at the garage sale was both the 9 th highest price and the 35 th lowest price among the prices of the items sold, how many items were sold at the garage sale ?
Options: a. 43, b. 28, c. 44, d. 49, e. 46
a

Problem: a couple who own an appliance store discover that if they advertise a sales discount of 10 % on every item in the store, at the end of one month the number of total items sold increases 15 %. their gross income from sales for one month increases by what percent ?
Options: a. 1.5 %, b. 2.5 %, c. 3.5 %, d. 4.5 %, e. 5.5 %
c

Problem: 3 pumps, working 8 hours a day, can empty a tank in 2 days. how many hours a day must 15 pumps work to empty the tank in 1 day ?
Options: a. 3.5, b. 4.8, c. 5.1, d. 5.2, e. 6.3

a