Word Problems - JSS2 Mathematics Lesson Note

Linear inequalities can be used to solve word problems involving constraints or limits.

Example 1: A company produces gadgets and wants to produce at least 50 gadgets but no more than 120 gadgets each day. 

Let 𝑥 represent the number of gadgets produced each day.

Write the inequality:

50≤𝑥≤120

This inequality means the number of gadgets produced (𝑥) must be between 50 and 120, inclusive.

Example 2: A student needs to score at least 70% on the next test to pass the course. Let 𝑥 represent the student's score.

Write the inequality:𝑥≥70

This inequality means the student's score (𝑥) must be at least 70%.

Example 3: John has a budget of $100 to spend on groceries. He wants to buy 𝑦 number of items that each cost $5. How many items can he buy?

Write the inequality:5𝑦≤100

Solve for 𝑦: 𝑦≤20

John can buy up to 20 items.

Example 4: A factory needs to produce at least 200 units but not more than 500 units of a product each day. Let 𝑧 represent the number of units produced.

Write the inequality:

200≤𝑧≤500

This inequality means the number of units produced (𝑧) must be between 200 and 500, inclusive.