The manager of a campus bookstore finds that in the last hour before closing, 41 students bought two or more textbooks. Of these 4 used cash only, 5 used a financial aid voucher only, and 5 used a debit card only. Seven used a debit card and financial aid voucher and no cash; three used cash and debit card with no financial aid assistance. Sixteen students total used a debit card for a least part of their purchase, while 9 used none of those forms of payment. (a) How many students used all of cash, debit card, and financial aid voucher?
(b) Did more students use cash or financial aid vouchers?
(c) What percentage of students did not use a financial aid voucher?

Martha has a deck of cards. she has lost some of the cards, and now the deck only contains nine spades, eleven diamonds, eight clubs, and twelve hearts. martha predicts that whenever she draws a card from the deck without looking, she will draw a club one-fifth of the time. which activity would best allow martha to test her prediction? a. randomly draw a card from the box and see if it is a club. b. randomly draw a card. then, continue to draw another card until all eight clubs are drawn. c. randomly draw and replace a card 120 times. then, observe how close to 30 times a club is drawn. d. randomly draw and replace a card 100 times. then, observe how close to 20 times a club is drawn.