MathDB

2

Part of 2011 May Olympiad

Problems(2)

4digit no, ab - cd = cd -ba May Olympiad (Olimpiada de Mayo) 2011 L2 P2

Source:

9/28/2021
We say that a four-digit number abcd‾\overline{abcd} (a≠0a \ne 0) is pora if the following terms are true : ∙\bullet a≥ba\ge b ∙\bullet ab−cd=cd−baab - cd = cd -ba. For example, 20112011 is pora because 20−11=11−0220-11 = 11-02 Find all the numbers around.
number theoryDigits
perfect square, cube by digits 1-9 May Olympiad (Olimpiada de Mayo) 2011 L1 P2

Source:

9/28/2021
Using only once each of the digits 1,2,3,4,5,6,71, 2, 3, 4, 5, 6, 7 and 8 8, write the square and the cube of a positive integer. Determine what that number can be.
Perfect Squareperfect cubesnumber theoryDigits