Mind challange when friends buys a car

  • #1
3
0
Four friends A, B, C and D are buying a car together.
They agree that everyone should have one of the first four trips all alone.

But the following conditions apply:

1. If D is allowed to get on the first trip, C would have the third trip.

2. If A or D take the second trip, C would have the first trip.

3. If and only if A receives the third trip, B want to have the second trip.

4. Will D get the third trip, A wants the second trip.

5. Will D get the last trip would C have the third and A the first.

In what possible orders can they take the first four trips so that all is happy?
Motivate your answer.

Good luck,folks! =)
 
  • #2
Welcome to PF, Grinder! :smile:

CABD, CDAB, or CDBA
 
  • #3
:smile: Thanks!

You have to justify the thought. Are there more? ;)

/Grinder
 
  • #4
CABD, CDAB, or CDBA
Unless I am misunderstanding the conditions, your first answer violates condition 5, and your second answer violates condition 3. Only your third answer satisfies all 5 conditions. Additionally there is
CADB

Justification is an exhaustive search of all possibilities :smile:
 
  • #5
Unless I am misunderstanding the conditions, your first answer violates condition 5, and your second answer violates condition 3. Only your third answer satisfies all 5 conditions. Additionally there is
CADB

Justification is an exhaustive search of all possibilities :smile:

Oops! I mistyped my first solution and miss checked my second solution. :redface:


:smile: Thanks!

You have to justify the thought. Are there more? ;)

/Grinder

No, there are no more:

It is easiest to verify the possibilities for D.
If D is first, the rules dictate uniquely when the others go, leading to a contradiction.
With D second, the order has to be CDBA.
With D third, CADB follows.
Finally with D 4th, we get another contradiction.
 
  • #6
Hi!

What about ACDB and BCDA then? :wink:

What conditions are they violate? Or do they satisfy all conditions?? :smile:

/Grinder:biggrin:


and yes...I found the smilie button!
 
  • #7
Hi!

What about ACDB and BCDA then? :wink:

What conditions are they violate? Or do they satisfy all conditions?? :smile:

/Grinder:biggrin:


and yes...I found the smilie button!

"4. Will D get the third trip, A wants the second trip."
 
  • #8
every one is wrong here... i will tell you how...
 
  • #9
go back read the question again and solve it...
 
  • #10
ACDB and BCDA is wrong
 
  • #11
It is easiest to verify the possibilities for D. but If D is first, the rules dictate uniquely when the others go, leading to a wrong answer.With D the order D has to be CDBA.With D third, CADB follows.Finally with D fourth, we get another wrong answer.
 
  • #12
Hi everyone,

Unless I am misreading the question, the answer is ABCD. To me the list of conditions is just that a list. IF this one does this than that one will be satisfied if he does this. In that case the only condition that has everyone happy in the end is condition 5 If D is last then C wants to be third and A wants to be first. That leaves B to be second.

Did I misread the question?
 
  • #13
Unless I am mis-reading this, the answer is CADB
 
  • #14
This one wasn't too hard. I came up with the following answer, if there's any flaws I'd like them to be pointed out.
CDBA
 
  • #15
CADB @@v hehe.. If I understood it correctly?
 
  • #16
I don't think that I understand this correctly
 

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