Question 85·Easy·Linear Inequalities in One or Two Variables
A community movie theater sets the price , in dollars, of an adult ticket so that it is greater than but no more than . Which inequality represents the possible adult ticket prices?
When translating word descriptions into inequalities, underline key phrases like “greater than,” “at least,” “less than,” and “no more than.” Decide whether each phrase includes the endpoint (use or ) or excludes it (use or ), then write a simple inequality for each part. Finally, combine the conditions into one compound inequality (with two inequality signs in one line) and pick the choice that matches it exactly, paying close attention to which endpoints are included or excluded.
Hints
Focus on the phrase about 8
Look at the words describing how compares to . Does “greater than ” allow to be equal to , or must it be strictly more than ? Which symbol fits: or ?
Focus on the phrase about 15
Now look at the words describing how compares to . Does “no more than ” allow to be equal to , or must it be strictly less than ? Which symbol fits: or ?
Put the two conditions together
Once you know how relates to and how it relates to , write both inequalities and think about how to show them together in a single statement. Then choose the option that matches that combined inequality.
Desmos Guide
Pick test prices from the description
From the words, choose a few prices that should be allowed (for example, and ) and a few that should not be allowed (for example, and ).
Test each option with a valid price
For each answer choice, replace with a valid price like and type that inequality into Desmos (for example, something like or , depending on the option). Desmos will tell you whether the statement is true or false. The correct inequality must be true for all valid prices you test.
Test each option with an invalid price
Now repeat the process with prices that should not be allowed, like and . For the correct option, Desmos should show the inequality is false for these invalid prices. The answer is the option that is true for all allowed values and false for the disallowed ones.
Step-by-step Explanation
Translate “greater than 8”
The problem says the price is greater than .
- “Greater than ” means must be more than , not equal to .
- In symbols, this is written as , which is the same as .
So one condition is that is strictly greater than (do not include ).
Translate “no more than 15”
The problem also says the price is no more than .
- “No more than ” means can be or any smaller value, but not larger.
- In symbols, this is written as .
So the second condition is that is less than or equal to (this does include ).
Combine both conditions and match the choice
Both conditions must be true at the same time:
- (greater than ), and
- (no more than ).
We can combine these into a single inequality:
This inequality exactly matches answer choice B) .