Chapter 2: Problem 1
The sizes of matrices \(A\) and \(B\) are given. Find the size of \(A B\) and \(B A\) whenever they are defined. \(A\) is of size \(2 \times 3\), and \(B\) is of size \(3 \times 5\).
/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none}
Learning Materials
Features
Discover
Chapter 2: Problem 1
The sizes of matrices \(A\) and \(B\) are given. Find the size of \(A B\) and \(B A\) whenever they are defined. \(A\) is of size \(2 \times 3\), and \(B\) is of size \(3 \times 5\).
All the tools & learning materials you need for study success - in one app.
Get started for free
An executive of Trident Com- munications recently traveled to London, Paris, and Rome. He paid $$\$ 180$$, $$\$ 230$$, and $$\$ 160$$ per night for lodging in London, Paris, and Rome, respectively, and his hotel bills totaled $$\$ 2660 .$$ He spent $$\$ 110$$, $$\$ 120$$, and $$\$ 90$$ per day for his meals in London, Paris, and Rome, respectively, and his expenses for meals totaled $$\$ 1520 .$$ If he spent as many days in London as he did in Paris and Rome combined, how many days did he stay in each city?
Let $$ A=\left[\begin{array}{ll} a & b \\ c & d \end{array}\right] $$ a. Find \(A^{-1}\) if it exists. b. Find a necessary condition for \(A\) to be nonsingular. c. Verify that \(A A^{-1}=A^{-1} A=I\).
For the opening night at the Opera House, a total of 1000 tickets were sold. Front orchestra seats cost $$\$ 80$$ apiece, rear orchestra seats cost $$\$ 60$$ apiece, and front balcony seats cost $$\$ 50$$ apiece. The combined number of tickets sold for the front orchestra and rear orchestra exceeded twice the number of front balcony tickets sold by 400. The total receipts for the performance were $$\$ 62,800$$. Determine how many tickets of each type were sold.
The problems in exercise correspond to those in exercises 15-27, Section 2.1. Use the results of your previous work to help you solve these problems. A dietitian wishes to plan a meal around three foods. The percent of the daily requirements of proteins, carbohydrates, and iron contained in each ounce of the three foods is summarized in the following table: $$\begin{array}{lccc} \hline & \text { Food I } & \text { Food II } & \text { Food III } \\ \hline \text { Proteins }(\%) & 10 & 6 & 8 \\ \hline \text { Carbohydrates }(\%) & 10 & 12 & 6 \\ \hline \text { Iron }(\%) & 5 & 4 & 12 \\ \hline \end{array}$$ Determine how many ounces of each food the dietitian should include in the meal to meet exactly the daily requirement of proteins, carbohydrates, and iron \((100 \%\) of each).
The property damage claim frequencies per 100 cars in Massachusetts in the years 2000,2001 , and 2002 are \(6.88,7.05\), and \(7.18\), respectively. The corresponding claim frequencies in the United States are 4.13, \(4.09\), and \(4.06\), respectively. Express this information using a \(2 \times 3\) matrix.
What do you think about this solution?
We value your feedback to improve our textbook solutions.