If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

## Precalculus

### Course: Precalculus>Unit 7

Lesson 6: Using matrices to manipulate data

# Use matrices to manipulate data

You might need: Calculator

## Problem

On two certain game shows, contestants can choose whether they want to answer an easy, intermediate or hard question. The harder the question, the more points they gain for answering correctly. However, if they get the question wrong, they are penalized by losing points.
Matrix $A$ represents the number of points contestants in game show $A$ can gain or lose (a negative number corresponds to losing points) for each type of question, where rows are difficulty level and columns are answer correctness.
Matrix $A$
${}_{\text{Difficulty}}{╲}^{\text{Answer}}$RightWrong
Easy$10$$-1$
Intermediate$30$$-5$
Hard$80$$-15$
Matrix $B$ represents the number of points contestants in game show $B$ can gain or lose for each type of question.
Matrix $B$
${}_{\text{Difficulty}}{╲}^{\text{Answer}}$RightWrong
Easy$12$$-2$
Intermediate$28$$-4$
Hard$100$$-20$
Matrix $C$ represents how many more (or less) points contestants gain (or lose) at game show $B$ compared to game show $A$ (where negative values mean contestants at game show $A$ gain more, or lose less, points).
Complete matrix $C$.
Matrix $C$
${}_{\text{Difficulty}}{╲}^{\text{Answer}}$RightWrong
Easy
Intermediate
$1$
Hard
Stuck?
Stuck?