When Jack sleeps, Jill starts crying and Peter starts laughing. If Peter is not laughing, which is the appropriate conclusion? | Sololearn: Learn to code for FREE!
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When Jack sleeps, Jill starts crying and Peter starts laughing. If Peter is not laughing, which is the appropriate conclusion?

a.Jack is not sleeping but Jill is crying b. Jack is not sleeping c. Jack is sleeping but Jill is not crying d. Jack is sleeping but Jill is crying. Please explain your answear

25th Nov 2016, 9:38 PM
Manolache Gabriel Ionuț
Manolache Gabriel Ionuț  - avatar
9 Answers
+ 2
an attempt... not sure a==true b=true && C==true if b !=true=> c== false a) a==false but b==true b)a== false c) a== true but b == false d)a == true but b== true ....a) a guess lol
26th Nov 2016, 12:33 AM
Abdoulaye Seck
Abdoulaye Seck - avatar
+ 2
I smell some logic going there ...lol
26th Nov 2016, 12:34 AM
Abdoulaye Seck
Abdoulaye Seck - avatar
+ 1
I think all should be correct. Example: On two sides of a card number and alphabet are written. If the side facing you has vowel other side is even. if side facing you is odd other side is consonant. So if you encounter 2 it does means other side is vowel. as question speaks of the reverse case and not this. so you can encounter an odd number, consonant, even or vowel on other side. So if Peter is not laughing anything could be there.
26th Nov 2016, 1:52 AM
Megatron
Megatron - avatar
26th Nov 2016, 8:29 AM
Manolache Gabriel Ionuț
Manolache Gabriel Ionuț  - avatar
+ 1
I found the question on another site: http://job-work-tests.makerise.net/?test=593 here the answers are given as A and B. The only thing I can say is that any answer that contains 'Jack is not sleeping' is POSSIBLY correct, like the following: 1. Jack is not sleeping 2. Jack is not sleeping, Jill is crying 3. Jack is not sleeping, Jill is not crying Apart from option 1, we do not have enough information to conclude on other two.
26th Nov 2016, 8:42 AM
Rill Chritty
Rill Chritty - avatar
+ 1
thanks for sharing
26th Nov 2016, 10:49 AM
Abdoulaye Seck
Abdoulaye Seck - avatar
0
You're all wrong , try again :)
26th Nov 2016, 7:46 AM
Manolache Gabriel Ionuț
Manolache Gabriel Ionuț  - avatar
0
Jack sleeping (A) => Jill crying (B) and Peter laughing (C), that is A=>B and A=>C. From logic theory, using the rule of converse of implication, that is X=>Y if and only if (<=>) Y'=>X', hence the only real conclusion we can make is C'=>A', that is Peter not laughing implies Jack not sleeping. We cannot make any logical conclusion about Jill using only the information provided, since there is no direct logical connection between Jill and Peter. Concluding that Jill is (or is not) crying is wrong. To see this from A=>(B and C), by converse we have (B and C)'=>A', and by de Morgen's rule, (B' or C')=>A'. So, we need at least one of B' or C' to be true, in order to conclude that A' is true; the condition is already satisfied by Peter not laughing (C' is true). The state of Jill does not affect this conclusion; this is easy to see: whether B' is true or false, (B' or C') is always true. Therefore no real conclusion can be made about Jill. Hence we can only conclude that Jack is NOT sleeping (option b).
26th Nov 2016, 8:02 AM
Rill Chritty
Rill Chritty - avatar
0
@Domagoj, you actually reversed the condition given in the question. It is supposed to be: while(Jack.sleeping) { Jill.crying = true; Peter.laughing = true; } although if would have more appropriate. Jack.sleeping is the condition (cause), which leads to (Jill.crying) and (Peter.laughing) - both are just consequences. so, if (Peter.laughing == false), that means we did not enter the loop, and for that to happen, it means that (Jack.sleeping = false). Nothing can be said about Jill.
26th Nov 2016, 8:16 AM
Rill Chritty
Rill Chritty - avatar