Grade 9 Matrix Addition & Subtraction Word Problems

A school is organizing a field trip and has 3 buses. The first bus can hold 25 students, the second bus can hold 30 students, and the third bus can hold 20 students. Represent the number of students each bus can hold as a matrix. If 10 students are added to the first bus and 5 are removed from the second bus, what is the new matrix representing the number of students in each bus?

• [[30], [25], [20]]

• [[25], [25], [20]]

• [[35], [30], [15]]

• [[35], [25], [20]]

A bakery produces two types of cakes: chocolate and vanilla. The production for chocolate cakes is represented by the matrix [[50], [60], [70]] and for vanilla cakes by [[30], [40], [50]]. If the bakery increases the production of chocolate cakes by 10 and decreases the production of vanilla cakes by 5, what is the resulting matrix for the production?

• [[70, 35], [80, 45], [90, 55]]

• [[60, 25], [70, 35], [80, 45]]

• [[55, 30], [65, 40], [75, 50]]

• [[50, 20], [60, 30], [70, 40]]

A company has two departments: Sales and Marketing. The Sales department has 15 employees and the Marketing department has 10 employees. Represent this as a matrix. If 5 employees are transferred from Sales to Marketing, what is the new matrix representing the number of employees in each department?

• [[15], [10]]

• [[10], [20]]

• [[10], [15]]

• [[5], [20]]

In a video game, a player earns points in two levels: Level 1 and Level 2. The points earned are represented by the matrix [[200, 150], [300, 250]]. If the player loses 50 points in Level 1 and gains 100 points in Level 2, what is the new points matrix?

• [[200, 150], [250, 300]]

• [[150, 150], [300, 300]]

• [[250, 250], [300, 200]]

• [[150, 250], [300, 250]]

A gym has two types of memberships: Basic and Premium. The number of members for each type is represented by the matrix [[120], [80]]. If 20 new Basic members join and 10 Premium members leave, what is the updated membership matrix?

• [[130], [80]]

• [[120], [90]]

• [[150], [60]]

• [[140], [70]]

A farmer has two fields: Field A and Field B. The yield from Field A is represented by the matrix [[100], [150]] and from Field B by [[80], [120]]. If the yield from Field A increases by 20 and from Field B decreases by 10, what is the new yield matrix?

• [[130], [160]]

• [[90], [130]]

• [[100], [150]]

• [[120], [170]], [[70], [110]]

A library has two sections: Fiction and Non-Fiction. The number of books in each section is represented by the matrix [[300], [200]]. If 50 Fiction books are added and 30 Non-Fiction books are removed, what is the updated matrix of books?

• [[300], [170]]

• [[350], [200]]

• [[300], [200]]

• [[350], [170]]

A factory produces two products: A and B. The production levels are represented by the matrix [[500], [300]]. If production of Product A increases by 100 and production of Product B decreases by 50, what is the new production matrix?

• [[600], [250]]

• [[700], [250]]

• [[500], [300]]

• [[600], [300]]

A school has two grades: 9th and 10th. The number of students in each grade is represented by the matrix [[200], [180]]. If 15 students move from 9th grade to 10th grade, what is the new matrix representing the number of students in each grade?

• [[200], [165]]

• [[185], [180]]

• [[190], [190]]

• [[185], [195]]

A restaurant has two types of meals: Vegetarian and Non-Vegetarian. The number of meals prepared is represented by the matrix [[120], [80]]. If 30 more Vegetarian meals are prepared and 20 Non-Vegetarian meals are sold out, what is the updated meal matrix?

• [[120], [80]]

• [[100], [70]]

• [[150], [80]]

• [[150], [60]]