Một xí nghiệp sản xuất độc quyền hai loại sản phẩm. Biết hàm cầu của hai loại sản phẩm trên lần lượt là 1 2 Q 45 2 ; Q 55 D D 1 2 1 2 P P P P và hàm chi phí kết hợp là 2 2 C Q +2 Q Q +Q +25Q . 1 1 2 2 2 Trong đó, P, Q 1,2 i i i lần lượt là đơn giá và sản lượng của sản phẩm thứ i . Tìm mức sản lượng của mỗi loại sản phẩm để xí nghiệp có lợi nhuận tối đa. Khi đó, giá bán các sản phẩm là bao nhiêu?

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.

Awoman has 14 different shirts: 10 white shirts and 4 red shirts. if she randomly chooses 2 shirts to take with her on vacation, then what is the probability that she will choose two white shirts? show your answer in fraction and percent, round to the nearest whole percent.

The dance committee of pine bluff middle school earns $72 from a bake sale and will earn $4 for each ticket they sell to the spring fling dance. the dance will cost $400 write an inequality to determine the number, t of tickets the committee could sell to have money left over after they pay for this year's dance. what is the solution set of the inequality?