What's her name?
Two girls have last names Billingsley and Jenkins. Not in a particular order, their first names are Sally and Susie. Two of the following are false:
Susie's last name is Billingsley.
Susie's last name is Jenkins.
Sally's last name is Jenkins.
What are the complete names of the girls?
Bonus question: How old are they if Sally has blonde hair? ... :)
Susie's last name is Billingsley.
Susie's last name is Jenkins.
Sally's last name is Jenkins.
What are the complete names of the girls?
Bonus question: How old are they if Sally has blonde hair? ... :)
posted by Zaux at
8:17 AM
12 Comments:
Sally Billingsley
Susie Jenkins
Sally and Billingsley as names both peaked in the UK in 1966, March. That would most likely put her at 43, going on for 44, having fun, trying to recapture her lost youth...
This post has been removed by the author.
Apparently, Sally Billingsley is, or has been, pregnant, according to her Facebook page:
link
And Susie Jenkins is a photographer:
link
Suzie Billingsley being correct is equivalent to Sally Jenkins being correct. So the first and third statements are equivalent. The second statement is equivalant to the negation of the first and third statements. So either the first and third are true and the second is false, or the first and third are false and the second is true. The latter is the only one that satisfies there being (at least) two false statements. So the second statement is true and then we have that it's Suzie Jenkins and Sally Billingsley ;)
My last post involved trial and error, so I don't like it.
Let ZB be truth value of Suzie Billingsley is correct. Note that Sally Jenkins is correct => !ZB is correct.
The three statemnts are ZB, !ZB and ZB.
We have two false statement and one true statement. This means that:
ZB.!!ZB.!ZB + !ZB.!ZB.!ZB + !ZB.!ZB.ZB = 1
But ZB.ZB = ZB and ZB.!ZB = 0 =>
0 + !ZB + 0 = 1 => ZB = 0.
i.e. Suzie isn't a Billingsley. So it's Suzie Jenkins and Sally Billingsley. QED
Karl was first with correct names, and Chris with the awesome analysis
Heck, I defer to Chris on this one! Great equation for analytical problem.
That was me above...
Chris, that looks like the hard way of doing this.
Easier to see that one of the first two statements must be true, so the last one is false, so . . .
I thank you ☺. I'm just amazed at how long winded the logical approach is. Take a look at logical way of doing No frills ... just Logic ... for an example.
Hi Wiz. I only did it for a joke (I assume you knew that).
LOL. Billingsley. Good name.
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