During the month of January, "ABC Appliances" sold 51 microwaves, 22 refrigerators and 34 stoves, while "XYZ Appliances" sold 36 microwaves, 27 refrigerators and 24 stoves, During the month of February, "ABC Appliances" sold 47 microwaves, 31 refrigerators and 25 stoves, while "XYZ Appliances" sold 50 microwaves, 34 refrigerators and 18 stoves, a. Write a matrix summarizing the sales for the month of January, (Enter in the same order that the information was given.) b. Write a matrix summarizing the sales for the month of February, (Enter in the same order that the information was given.)

20. Jumlah 20 suku pertama suatu deret aritmetika ialah 500. Jika suku pertama ialah 5 maka suku terakhir deret itu adalah A. 35 B. 39 C. 45 D. 48 E. 52

Leon knows that his first four test grades were \( 92,91,85 \), and 95 . Use the formula \( \bar{x}=\frac{x_{1}+x_{2}+\ldots+x_{n}}{n} \) to find Leon's grade on the fifth test if his test average is 91.2 .

18. Diketahui suku ke-3 dan suku ke-5 dari barisan aritmetika secara berturut-turut adalah -5 dan -9 . Suku ke-10 dari barisan tersebut adalah A. 20 B. 19 C. 17 D. -19 E. -20

Questão 2. Jogar baralho é uma atividade que estimula o raciocinio. Um jogo tradicional é a Paciència, que utiliza 52 cartas. Inicialmente são formadas sete colunas com as cartas. A primeira coluna tem uma carta, a segunda tem duas cartas, a terceira tem três cartas, a quarta temı quatro cartas, e assim sucessivamente até a sétima coluna, a qual tem sete cartas, e o que sobra forma o monte, que são as cartas não utilizadas nas colunas. A quantidade de cartas que forma o monte é \( \begin{array}{lll}\text { A. } 21 & \text { C. } 26 \\ \text { B. } 24 & \text { D. } 28 & \text { E. } 31\end{array} \)

20. Jumlah 20 suku pertama suatu deret aritmetika ialah 500 . Jika suku pertama ia maka suku terakhir deret itu adalah A. 35 B. 39 C. 45 D. 48 E. 52