Introduction to logic 14th edtion, Irving M. Copi Carl Cohen, Ch2.4 2E Of three

Question

Introduction to logic 14th edtion, Irving M. Copi Carl Cohen,

Ch2.4 2E

Of three prisoners in a certain jail, one had normal vision, the second
had only one eye, and the third was totally blind. The jailor told the
prisoners that, from three white hats and two red hats, he would select
three and put them on the prisoners’ heads. None could see what color
hat he wore. The jailor offered freedom to the prisoner with normal vision
if he could tell what color hat he wore. To prevent a lucky guess,
the jailor threatened execution for any incorrect answer. The first prisoner
could not tell what hat he wore. Next the jailor made the same offer
to the one-eyed prisoner. The second prisoner could not tell what hat he
wore either. The jailor did not bother making the offer to the blind prisoner,
but he agreed to extend the same terms to that prisoner when he
made the request. The blind prisoner said:
I do not need to have my sight;
From what my friends with eyes have said,
I clearly see my hat is _____!
How did he know?

Explanation / Answer

First we represent white caps by W and red caps by R

as first one has full vision so he can see the other two peoples head so when he says he dont the color of his hat that means other two persons hat color possibilities are

1.both one eye person and blind person have white color cap

or

2.one have red color while other have red

when one eye person see the color of blind person hat and said he dont the color of his hat that means he seen the white color hat on blind person head because if it was red then that means his cap color must be white then he did not say he dont know

so from those observations third one (blind) get that his cap color is white

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.