Code: PU
P=100 (k=89=1 (mod 11) )
Formulae:
Number N is divisible by 11 iff sum of digits is divisible by 11
Example:
Number N =
98 76 54 32 04
10+10+10+10+4 = 44 = 0 (mod 11)
is divisible by 11.
Number N =
10 23 07 29
10+1+7+7 = 25 = 3 (mod 11)
isn't divisible by 11.
Code: PD
P=10, (k=1)
Formulae:
Number N is divisible by 11 iff alternating sum of digits is divisible by 11
Example:
Number N =
9 8 7 6 5 4 3 2 1 5
-9+8-7+6-5+4-3+2-1+5 = 0 (mod 11)
is divisible by 11.
Number N =
5 3 1 9 7 6 2
5-3+1-9+7-6+2 = -3 = 8 (mod 11)
isn't divisible by11.
Code: SN, PD in P=1000 (k=1 special) 1001 = 7*11*13
Compare with divisibility rule by 7
Formulae:
Number N is divisible by 11 iff remainder from division by 1001 is divisible by 11
