Chapter 4, Problem 7PT

a.

To determine

To calculate: The total amount paid for books by him.

Answer to Problem 7PT

The total amount paid for books by himis $\$2060$ .

Explanation of Solution

Given information:

A table that depicts the cost and selling price of different books.

  $\begin{array}{ccc}\text{Type of Book}& \text{Cost}& \text{Selling price}\\ \text{Encyclopedia set}& \$35& \$105\\ \text{Science books}& \$25& \$85\\ \text{Literature books}& \$40& \$125\end{array}$

20 sets of encyclopedias, 32 sets of science books and 14 sets of literature books were sold by him.

Calculation:

Consider the provided information thata table that depicts the cost and selling price of different books.

  $\begin{array}{ccc}\text{Type of Book}& \text{Cost}& \text{Selling price}\\ \text{Encyclopedia set}& \$35& \$105\\ \text{Science books}& \$25& \$85\\ \text{Literature books}& \$40& \$125\end{array}$

20 sets of encyclopedias, 32 sets of science books and 14 sets of literature books were sold by him.

Construct a row matrix and each column of it represent the number of each book sold.

  $\left[\begin{array}{ccc}20& 32& 14\end{array}\right]$

The dimension of the matrix obtained above is $1\times 3$ .

Denote the three rows of the matrix as three different books and 1 column as cost of the books.

  $\left[\begin{array}{c}35\\ 25\\ 40\end{array}\right]$

Therefore, the he total amount paid for books by him is the multiplication of number of each book by its cost.

  $\begin{array}{c}\left[\begin{array}{ccc}20& 32& 14\end{array}\right]\left[\begin{array}{c}35\\ 25\\ 40\end{array}\right]=20\left(35\right)+32\left(25\right)+14\left(40\right)\\ =2060\end{array}$

Thus, the total amount paid for books by him is $\$2060$ .

b.

To determine

To calculate: The total amount paid for books by buyer.

Answer to Problem 7PT

The total amount paid for books by buyeris $\$6570$ .

Explanation of Solution

Given information:

A table that depicts the cost and selling price of different books.

  $\begin{array}{ccc}\text{Type of Book}& \text{Cost}& \text{Selling price}\\ \text{Encyclopedia set}& \$35& \$105\\ \text{Science books}& \$25& \$85\\ \text{Literature books}& \$40& \$125\end{array}$

20 sets of encyclopedias, 32 sets of science books and 14 sets of literature books were sold by him.

Calculation:

Consider the provided information thata table that depicts the cost and selling price of different books.

  $\begin{array}{ccc}\text{Type of Book}& \text{Cost}& \text{Selling price}\\ \text{Encyclopedia set}& \$35& \$105\\ \text{Science books}& \$25& \$85\\ \text{Literature books}& \$40& \$125\end{array}$

20 sets of encyclopedias, 32 sets of science books and 14 sets of literature books were sold by him.

Construct a row matrix and each column of it represent the number of each book sold.

  $\left[\begin{array}{ccc}20& 32& 14\end{array}\right]$

The dimension of the matrix obtained above is $1\times 3$ .

Denote the three rows of the matrix as three different books and 1 column as selling price of the books.

  $\left[\begin{array}{c}105\\ 85\\ 125\end{array}\right]$

Therefore, the he total amount paid for books by him is the multiplication of number of each book by its cost.

  $\begin{array}{c}\left[\begin{array}{ccc}20& 32& 14\end{array}\right]\left[\begin{array}{c}105\\ 85\\ 125\end{array}\right]=20\left(105\right)+32\left(85\right)+14\left(125\right)\\ =6570\end{array}$

Thus, the total amount paid for books by buyeris $\$6570$ .

c.

To determine

To calculate: The total amount paid he made on his sales.

Answer to Problem 7PT

The total amount paid he made on his salesis $\$4510$ .

Explanation of Solution

Given information:

A table that depicts the cost and selling price of different books.

  $\begin{array}{ccc}\text{Type of Book}& \text{Cost}& \text{Selling price}\\ \text{Encyclopedia set}& \$35& \$105\\ \text{Science books}& \$25& \$85\\ \text{Literature books}& \$40& \$125\end{array}$

20 sets of encyclopedias, 32 sets of science books and 14 sets of literature books were sold by him.

Calculation:

Consider the provided information that a table that depicts the cost and selling price of different books.

  $\begin{array}{ccc}\text{Type of Book}& \text{Cost}& \text{Selling price}\\ \text{Encyclopedia set}& \$35& \$105\\ \text{Science books}& \$25& \$85\\ \text{Literature books}& \$40& \$125\end{array}$

20 sets of encyclopedias, 32 sets of science books and 14 sets of literature books were sold by him.

Construct a row matrix and each column of it represent the number of each book sold.

  $\left[\begin{array}{ccc}20& 32& 14\end{array}\right]$

The dimension of the matrix obtained above is $1\times 3$ .

Denote the three rows of the matrix as three different books and 1 column as cost of the books.

  $\left[\begin{array}{c}35\\ 25\\ 40\end{array}\right]$

Therefore, the he total amount paid for books by him is the multiplication of number of each book by its cost.

  $\begin{array}{c}\left[\begin{array}{ccc}20& 32& 14\end{array}\right]\left[\begin{array}{c}35\\ 25\\ 40\end{array}\right]=20\left(35\right)+32\left(25\right)+14\left(40\right)\\ =2060\end{array}$

Denote the three rows of the matrix as three different books and 1 column as selling price of the books.

  $\left[\begin{array}{c}105\\ 85\\ 125\end{array}\right]$

Therefore, the he total amount paid for books by him is the multiplication of number of each book by its cost.

  $\begin{array}{c}\left[\begin{array}{ccc}20& 32& 14\end{array}\right]\left[\begin{array}{c}105\\ 85\\ 125\end{array}\right]=20\left(105\right)+32\left(85\right)+14\left(125\right)\\ =6570\end{array}$

The total amount paid he made on his sales is the difference between the cost and selling price.

  $\$6570-\$2060=\$4510$

Thus, the total amount paid he made on his sales is $\$4510$ .