Question

Shelly, Jess, and Andrea are all working at an amusement park for the summer. The manager finds out that one of them left the key in the door to the security office. When he asked them who did it, they replied:

Shelly: Andrea did it.
Jess: Shelly did not do it.
Andrea: I didn’t do it.

The manager believed Andrea. Use an indirect proof to show that Andrea did not leave the key in the security office door.

Hint: Begin by assuming Andrea did leave the key in the door.

Answer 1

@ganeshie8

Answer 2

Since we want to prove that Andrea did not leave the key in the door, lets start by assuming the opposite is true - that "Andrea did leave the key in the door."

Answer 3

Ok so now what

Answer 4

then, check the truth values of each of the given statements :-
Shelly: Andrea did it. (TRUE/FLASE ?)
Jess: Shelly did not do it. (TRUE/FALSE ?)
Andrea: I didn’t do it. (TRUE/FALSE ?)

Answer 5

I want you fill them using the assumption that "Andrea left the key in door"

Answer 6

Shelly true
Jess false
Andrea false

Answer 7

So now what?

Answer 8

wrong, check Jess again.

Answer 9

Is Jess statement really contradicting our assumption ?

Answer 10

Oh ya so whats the final product after we got all this information

Answer 11

Shelly: Andrea did it. (TRUE)
Jess: Shelly did not do it. (TRUE)
Andrea: I didn’t do it. (FALSE )

Answer 12

That's the final answer to this problem?
Sorry im confused

Answer 13

no, we completed oly 2 steps. 3rd step is still there.

Answer 14

Since we got one FALSE, thats a contradiction to our assumption that "Andrea did leave the key". So our assumption is incorrect. So the opposite must be true. So Andrea did not leave the key in the security office door.

Answer 15

ok so whats the third step :)

Answer 16

here the whole proof, have a look :-

step1 :
Since we want to prove that Andrea did not leave the key in the door, lets start by assuming the opposite is true - that Andrea did leave the key in the door.

step 2:
then, check the truth values of each of the given statements :-
Shelly: Andrea did it. (TRUE)
Jess: Shelly did not do it. (TRUE)
Andrea: I didn’t do it. (FALSE)

step 3:

Since we got one FALSE, thats a contradiction to our assumption that Andrea did leave the key. So our assumption is incorrect. So the opposite must be true. So Andrea did not leave the key in the security office door.

Answer 17

All those steps= my final answer?

Answer 18

Yes, in indirect proof you need to show those 3 steps : 1) assumption 2) contradiction 3) conclude

Answer 19

Wait can I ask u another question plz? ill medal

Answer 20

you can ask. medal not required :)

Answer 21

You have been hired as contractors for your uncle's company. Your first day on the job you get a call from the Noether family who would like to install a pool in their backyard. Your job is to design the pool and provide some cost estimates.

Answer 22

The pool should be a rectangular prism. Mrs. Noether wants the pool to hold between 1400 ft3 and 3200 ft3 of water and be from 6-10 feet deep. Other than those specifications, you are free to design the pool how you'd like!

The estimated cost of the pool, besides labor, will come from the pool lining material that coats the inside of the pool and the amount of water needed to fill the pool. Determine the following:
1.The dimensions for the Noether pool that fit the above specifications
2. The amount of pool liner material that will be needed to completely line the inside of the pool (sides and bottom)
3. The amount of water that will be needed to fill the pool if the water needs to be 6 inches below the top of the pool

*Please include the work involved in determining the above measurements or an explanation for how the measurements were determined.

Draft a proposal for the Noethers that includes the above information along with a drawing of their pool. You may need to create more than one drawing to correctly convey your idea.

Answer 23

this is a module activity which i worked wid many students before and i got bored. post a separate q, hope somebody helps u :)

Answer 24

OK no prob:) I got some more questions if you and your smart brain can help me:)

Answer 25

Given: ∆ABC

Prove: The three medians of ∆ABC intersect at a common point.

When written in the correct order, the two-column proof below describes the statements and justifications for proving the three medians of a triangle all intersect in one point.




Statements

Justifications




Point F is a midpoint of Line segment AB

Point E is a midpoint of Line segment AC

Draw Line segment BE

Draw Line segment FC

by Construction




Point G is the point of intersection between Line segment BE and Line segment FC

Intersecting Lines Postulate




Draw Line segment AG

by Construction




Point D is the point of intersection between Line segment AG and Line segment BC

Intersecting Lines Postulate




Point H lies on Line segment AG such that Line segment AG ≅ Line segment GH

by Construction


I

BGCH is a parallelogram

Properties of a Parallelogram (opposite sides are parallel)


II

Line segment BD ≅ Line segment DC

Properties of a Parallelogram (diagonals bisect each other)


III

Line segment GC is parallel to line segment BH and Line segment BG is parallel to line segment HC

Substitution


IV

Line segment FG is parallel to line segment BH and Line segment GE is parallel to line segment HC

Midsegment Theorem




Line segment AD is a median

Definition of a Median


Which is the most logical order of statements and justifications I, II, III, and IV to complete the proof?
III, IV, II, I

IV, III, I, II

III, IV, I, II

IV, III, II, I

Answer 26

@ganeshie8 Can you help?

Answer 27

I've answered this also previously.
you can find the solution for this here :-

http://openstudy.com/study#/updates/50509fd7e4b0bea4300650b9

Answer 28

That's the same format but different question. I need help on this exact one. Please I will medal

Answer 29

thats the same q, i dont see any difference hmm

Answer 30

The answer choices are different

Answer 31

i knw i dont want to give u answer anyways. i want to help u in figuring out answer

Answer 32

OK but I don't get how u solved that problem

Answer 33

have a look again. if u still dont get, ask me what u dont get, maybe we can start from there :)