Lucy purchased a prepaid phone card for $30. Long distance calls cost 21 cents a minute using this card. Lucy used her card only once to make a long distance call. If the remaining credit on her card is $27.27, how many minutes did her call last?

At a sand and gravel plant, sand is falling off a conveyor and onto a conical pile at a rate of 16 cubic feet per minute. the diameter of the base of the cone is approximately three times the altitude. at what rate is the height of the pile changing when the pile is 12 feet high? (hint: the formula for the volume of a cone is v = 1 3 πr2h.)

Students are given 3 minutes for each multiple-choice question and 5 minutes for each free-response question on a test. there are 15 questions on the test, and students are given 51 minutes to take it.how many multiple-choice questions are on the test?

The graph shown is the graph of which function?