This test has 8 questions worth 20 points and takes about 45 minutes. Show every row-by-column calculation, and write matrices with brackets. A calculator is allowed for arithmetic. The questions cover data matrices, operations, products, determinants and inverses.
- Grade: Precalculus
- Chapter: Matrices and Matrix Operations
- Common Core: N-VM.C.6, N-VM.C.7, N-VM.C.8, N-VM.C.9, N-VM.C.10
- Time: 45 minutes
- Total: 20 points (Question 1: 2 pts; Question 2: 2 pts; Question 3: 2 pts; Question 4: 3 pts; Question 5: 2 pts; Question 6: 2 pts; Question 7: 3 pts; Question 8: 4 pts)
Question 1: Write a data matrix (2 points)
The table shows game statistics.
| Player | Points | Rebounds | Assists |
|---|---|---|---|
| Aisha | 18 | 7 | 4 |
| Ethan | 12 | 9 | 6 |
- Write a matrix with one row per player and state its dimensions. (1 point)
- State the entry in row 2, column 3 and what it means. (1 point)
Question 2: Add and scale matrices (2 points)
Use the matrices below.
- Find \(A+B\). (1 point)
- Find \(3A-2B\). (1 point)
Question 3: Solve for unknowns (2 points)
Find \(a\), \(b\) and \(c\).
Question 4: Multiply matrices (3 points)
Use the matrices below.
- State the dimensions of \(RS\). (1 point)
- Find \(RS\). (2 points)
Question 5: Order of multiplication (2 points)
Find \(AB\) and \(BA\) for the matrices below, and state whether they are equal.
Question 6: Determinants and invertibility (2 points)
For each matrix, find the determinant and state whether the matrix has an inverse.
Question 7: Find and verify an inverse (3 points)
Use matrix \(M\).
- Find \(\det M\). (1 point)
- Find \(M^{-1}\). (1 point)
- Verify by computing \(MM^{-1}\). (1 point)
Question 8: Smoothie stand revenue (4 points)
Sofia sells small, medium and large smoothies. Matrix \(S\) gives the number sold on Saturday and Sunday. Matrix \(P\) gives the prices in dollars.
- State the dimensions of \(SP\) and what each entry represents. (1 point)
- Find \(SP\). (2 points)
- Find the total revenue for both days. (1 point)
See every chapter on the Precalculus math page.


