Scarcity, choices and opportunity cost

Grade 12 Social Studies Worksheet - Building Confidence

Circle the best answer.

1. Read this first

   Use this

   Mari's Saturday (example figures, made up for practice). Columns: Choice, Pay, Mari's rank (1 = most wanted). Tutoring, $15 an hour, 1; Yard work, $12 an hour, 2; Band practice, $0, 3; Movie with friends, $0, ticket $10, 4. Mari has six free hours and can do one choice for all six. The ranks are her own. Opportunity cost is the value of the next-best choice given up.

2. 1.

   Mari picks tutoring for all six hours. Ari asks what Mari's opportunity cost is. Which answer fits the table?

   • Band practice and the movie together, since she gives up each other choice at once
   • The $15 an hour she earns, since that is the price she pays for choosing tutoring
   • Yard work, her second choice, for the same six hours
   • Nothing, since she is paid for tutoring and so loses no money by choosing it
3. 2.

   Mari says, "Tutoring costs me nothing because I get paid." Esme tests the claim. What is the best reply?

   • Not so: tutoring uses six hours she could have spent on yard work, her next-best choice
   • Right: she is paid more than yard work would pay, so her cost drops to zero
   • Not so: she must also add the band practice she misses, which has a cost of its own as well
   • Right: opportunity cost counts only money spent, and tutoring costs her no money
4. 3.

   Jun asks how much better off Mari is with tutoring than with her next-best choice for the six hours. Which answer fits the table?

   • $72 better off, the pay from yard work that she gives up by choosing tutoring
   • $18 better off: $90 from tutoring against the $72 that yard work would pay
   • $162 better off, the pay from tutoring and yard work together
   • $90 better off, the full pay from six hours of tutoring at $15 an hour

5. Use this

   Lemonade batches (10 cups each) (example figures, made up for practice). Columns: Batches, Total cost, Total sales. 1, $12, $20; 2, $22, $40; 3, $34, $60; 4, $50, $80; 5, $72, $100. Each batch sells for $20. A $15 sign was bought yesterday; it is not in the costs. The rule: make one more batch only while its extra sales are above its extra cost.

6. 4.

   Kira wants the number of batches that earns the most profit. Which choice does the table support?

   • Three batches, since total sales are $26 above total cost there by the widest margin
   • Two batches, since the average cost per batch is lowest there at $11
   • Four batches, because the 5th adds $22 in cost for $20 in sales
   • Five batches, since total sales rise with each batch and reach $100
7. 5.

   Milo compares four batches with five. Which statement about profit does the table support?

   • Four batches earn $30 profit and five earn $28, so the extra batch lowers profit
   • Four batches earn $26 and five earn $30, so profit is still rising at five
   • Four batches earn $30, but the table gives no way to tell what five batches would earn
   • Four batches earn $80 and five earn $100, so the fifth batch raises profit
8. 6.

   Zee says the average cost for five batches is $13.20, below the $20 each batch sells for, so make five. Noah replies. What is the best reply?

   • Sound: when average cost is below the selling price, each added batch earns a profit
   • Not sound: the rule compares the next batch's cost, $22, with its sales, $20
   • Sound: sales rise with each batch, so a fifth batch cannot lose any money
   • Not sound: average cost is $13.20 just if the $15 sign is counted, and it is not

9. The town's three projects (example figures, made up for practice)

   Project	Cost	Survey score (points)
   Library hours	$60,000	70
   Road repair	$50,000	65
   Park lights	$40,000	40

   The town has $100,000 and can pay for any projects whose costs fit. Scarcity means wants are greater than the resources available. A shortage means that at the market price buyers want more than sellers offer.

10. 7.

    Pia wants the set of projects that gives the town the most survey points within its $100,000. Which set is it?

    • Library hours and park lights, which fit the budget and total 110 points
    • Library hours and road repair, the two highest scores, for 135 points
    • Library hours alone, since it has the highest score of the three projects
    • Road repair and park lights, since together they cost least and total 105 points
11. 8.

    The town funds the library and the park lights. Ren asks for the opportunity cost of that choice. Which answer fits?

    • 105 points, the road repair and park lights bundle that the same money could buy
    • 175 points, the three survey scores summed as the cost of making any one choice
    • 65 points, the road repair alone, since it is the project left unfunded
    • 110 points, the survey total of the projects that the town does choose
12. 9.

    A caller says the town has a shortage because it cannot fund all three projects. Tala checks the definitions. Which answer fits?

    • It is scarcity: wants exceed what the town can pay for, with no market price involved
    • It is neither, since scarcity applies to goods that people buy in a market
    • It is a shortage: the projects are priced at their cost, and buyers want more than sellers offer
    • It is a shortage: anyone who cannot get what they want faces a shortage of it
13. 10.

    A resident says the scores prove each resident values library hours more than park lights. Zee tests the claim. What is the verdict?

    • Supported: 70 is greater than 40, so each resident ranks the library above the park lights
    • Not supported: survey scores cannot be used to compare projects in any way at the town level
    • Supported: the library costs more, so it must be worth more to the residents who vote
    • Not supported: scores are survey results, so some residents may value park lights more