Question 34·Easy·Linear Inequalities in One or Two Variables
At a local movie theater, child tickets cost $8 each and adult tickets cost $12 each. A family plans to spend no more than $60 on tickets. If child tickets and adult tickets are purchased, which of the following inequalities must represent this situation?
For word problems that ask for an inequality, first write an algebraic expression for the total quantity (here, total cost) by multiplying each item's price by its number and adding them. Then carefully translate key phrases: "no more than" and "at most" mean , while "at least" and "no less than" mean . Finally, match both the correct expression (with the right coefficients attached to the right variables) and the correct inequality symbol to the choice, watching for traps where numbers are swapped or the inequality sign is reversed.
Hints
Find the total cost in terms of and
Write an expression for how much is spent on child tickets and on adult tickets, then add them to get the total in terms of and .
Interpret the phrase "no more than $60"
Does "no more than" mean the total must be at least $60, or at most $60? Decide whether that corresponds to or .
Match the expression and inequality to a choice
Once you know the correct expression for total cost and which inequality symbol fits the phrase, look for the option that uses both of those correctly.
Desmos Guide
Represent the total cost in Desmos
Let stand for (child tickets) and stand for (adult tickets). In Desmos, type 8x + 12y on one line to represent the total ticket cost.
Compare the two possible inequality directions
Type 8x + 12y <= 60 on one line and 8x + 12y >= 60 on another. Desmos will draw a boundary line and shade one side for each inequality.
Decide which shading matches "no more than $60"
Think about combinations like , which cost (under $60), and , which costs $64 (over $60). The correct inequality is the one whose shaded region includes points with total cost $60 or less and excludes points with total cost greater than $60.
Use the expression to eliminate coefficient mistakes
Notice that in your Desmos inequalities you used 8x + 12y, which matches the given prices. Any answer choice that has 12c + 8a on the left side does not correctly represent the total cost and should be ruled out.
Step-by-step Explanation
Write the cost for each type of ticket
Each child ticket costs $8, so child tickets cost dollars.
Each adult ticket costs $12, so adult tickets cost dollars.
Write an expression for the total cost
The total amount the family spends on tickets is the sum of the child-ticket cost and the adult-ticket cost:
.
Translate "no more than $60" into an inequality symbol
"No more than $60" means the total can be $60 or any smaller amount, but not more.
This is written with the less than or equal to symbol: .
Combine the expression and the inequality and match the choice
Put the total cost expression together with the inequality from the wording:
.
This matches choice A) .