Word Version Below
Extra Practice with 2.1 and 2.4 Name _______________________________
Determine if statement (3) follows from statements (1) and (2) by either the Law of Detachment or Law of Syllogism. If it does, state which law was used. If it does not, write invalid.
1. (1) If an angle measures more than 90 , then it is not acute.
(2) m ABC 120 .
(3) ABC is not acute.
2. (1) All 45 angles are congruent.
(2) A B
(3) A and B are 45
3. (1) If you order the apple pie, then it will be served with ice cream.
(2) Matthew ordered the apple pie.
(3) Matthew was served ice cream.
4. (1) If you wear the school colors, then you have school spirit.
(2) If you have school spirit, then the team feels great.
(3) If you wear the school colors, then the team will feel great.
5. (1) If you can eat too much turkey, then you will get sick.
(2) Kinsley got sick.
(3) Kinsley ate too much turkey.
6. (1) If 2 is acute, then 3 is obtuse.
(2) If 3 is obtuse, then 4 is acute.
(3) If 2 is acute, then 4 is acute.
In problems 7-10, decide whether inductive or deductive reasoning is used to reach the conclusion. Explain your reasoning.
7. Angela knows that Walt is taller than Peter. She also knows that Peter is taller than Natalie. Angela reasons that Walt is taller than Natalie.
8. Josh know that Brand X computers cost less than Brand Y computers. All other brands that Josh knows of cost less than Brand X. Josh reasons that Brand Y cost more than all the other brands..
9. For the past three Wednesdays, the cafeteria has served macaroni and cheese for lunch. Dana concludes that the cafeteria will serve macaroni and cheese for lunch this Wednesday.
10. If you live in Nevada and are between the ages of 16 and 18, then you must take driver’s education to get your license. Anthony lives in Nevada, is 16 years old, and has his driver’s license. Therefore, Anthony took driver’s education.
Use law of detachment to make a valid conclusion in the situation.
11. If you get a hit, then your baseball team will win. You hit a home run.
12. If Rylee gets promoted, then Callie will also be promoted. Rylee is promoted.
13. Any time Kendra runs in a cross country race, if she runs a strong race, then she wins. In the cross country race last Saturday, Kendra ran her best race.
14. If two integers are added together, then the result is an integer. You add an integer x to another integer y. The sum is an integer. 15. If you double a negative number, then the result is a smaller number.
Use the law of Syllogism to write the statement that follows from the pair of statements that are given.
17. If Moose is hungry when he goes to the pizza shop, then he’ll finish a whole pizza. If Moose eats a whole pizza, then he goes through a pitcher of soda.
18. If you mail the payment by noon, then it will arrive by tomorrow. If your payment arrives by tomorrow, then you won’t be charged a late fee.
19. If Estelle takes her broker’s advice, she’ll invest in stock X. If Estelle invests in stock X, she’ll earn 50% on her investment by next year.
20. If a triangle has two angles of 60° , then the triangle is equiangular. If a triangle is equiangular, then it is also equilateral.
Decide whether the conclusion reached from the two statements demonstrates the Law of Detachment, the Law of Syllogism, or neither.
21. If Cedric plays in a big game, then he gets nervous. If Cedric gets nervous, then he performs well. Conclusion: If Cedric plays in a big game, then he performs well.
22. If Leanne spends more than $30 on her car, then she’ll have to wait until next week to buy Michael’s birthday gift. Leanna spent $40 on her car. Conclusion: Leanne will have to wait until next week to buy Michael’s birthday gift.
23. If Lavonne gets money, she gives half of it to Sid. If Sid gets money, he gives half of it to Lavonne. Conclusion: Lavonne and Sid share their money equally.