Find P: P corresponds to prime digits

  • Thread starter Thread starter rajesh
  • Start date Start date
  • Tags Tags
    Prime
AI Thread Summary
The discussion revolves around solving a mathematical problem involving the expression "7P5 x 33 = PPPP" where P represents prime digits. Participants analyze the implications of the equation, noting that if P is a prime digit, it must end in '5' based on the multiplication of 5 by 3. However, the addition of two identical terms (PPPP + PPPP) leads to a contradiction, as it suggests P must also end in '0', which is impossible for a prime digit. Further calculations show that the product of "7P5 x 33" must fall within the range of 2000 to 3000, indicating P could be 2. Yet, since a prime digit must also end in '5', this creates a conflict, reinforcing the conclusion that the problem may have been copied incorrectly or is unsolvable as presented.
rajesh
Messages
19
Reaction score
0
P corresponds to prime digits(i donno what thi means...i am giving exactly as given in a test)

7P5
x33
---------
PPPP
PPPP
----------
PPPPP


Find the value of P?
 
Physics news on Phys.org
rajesh said:
P corresponds to prime digits(i donno what thi means...i am giving exactly as given in a test)

7P5
x33
---------
PPPP
PPPP
----------
PPPPP


Find the value of P?

Let's suppose P is a string of digits.
From 5x3 -> P ends in a '5'
From PPPP+PPPP = PPPPP -> P ends in a '0'

So it's impossible.
 
actually i could not put the correct indentation(i am new to this site)...

somebody tell me how to attach a file
 
Is this what you want ?

Code:
             7 P 5
             x 3 3
         ---------
           P P P P             
         P P P P
        ----------
         P P P P P
 
Even with the indentation (enclose within [ code] [ /code] tags), there would be no solution, as you would have PPPP + PPPP0 = PPPPP.

Why is this impossible ?

PPPP -> 1000P+100P+10P+P = 1111P and similarly PPPP0 ->11110P, so adding should give 12221P, but clearly PPPPP -> 11111P, a contradiction, unless P=0. But clearly P can't be 0.
 
I think you haven't copied the problem down correctly...

Here's another reason why this is wrong (if you're not happy with the previous ones) :

700 X 33 = 23100
800 X 33 = 26400

So clearly 7P5 X 33 must be in the 2 thousands, therefore P must be 2. But also, any multiple of 5 must end with 5, so P must be 5. A contradiction !
 
Last edited:
Thread 'RIP Chen Ning Yang (1922-2025)'
https://en.wikipedia.org/wiki/Yang_Chen-Ning ( photo from http://insti.physics.sunysb.edu/~yang/ ) https://www.nytimes.com/2025/10/18/science/chen-ning-yang-dead.html https://www.bbc.com/news/articles/cdxrzzk02plo https://www.cpr.cuhk.edu.hk/en/press/mourning-professor-yang-chen-ning/ https://www.stonybrook.edu/commcms/physics/about/awards_and_prizes/_nobel_and_breakthrough_prizes/_profiles/yangc https://www.stonybrook.edu/commcms/physics/people/_profiles/yangc...
Back
Top