Consider a matrix nXn representing a multiplication table i.e. a_ij=i*j .
Determine the number of appearances of n in this matrix.

(In reply to re: Solution by Ady TZIDON)

For 6×6, with 6 having 4 divisors, the formula D+2n gives 4+2(6)=16

1×6 =  6 : 2  
2×3 =  6 : 1
2×6 = 12 : 1
3×2 =  6 : 1
3×6 = 18 : 1
4×6 = 24 : 1
5×6 = 30 : 1
6*1 =  6 : 2
6*2 = 12 : 1
6*3 = 18 : 1
6*4 = 24 : 1
6*5 = 30 : 1
6*6 = 36 : 2
   TOTAL  16 occurances of the number 6

Posted by Dej Mar on 2012-12-13 05:14:04