Divisibility ?

1 Answer
Jun 11, 2016

n_1 = 12132n1=12132 and n_2 = 12636n2=12636

Explanation:

A number nn is divisible by 44 when the number formed by its two right digits is divisible by 44 and the same number nn is divisible by 99 when the sum of its digits is divisible by 99.

We have

c_1->3 xx 10 + diamond = 4 xx k_1c13×10+=4×k1
c_2->1+2+square+3+diamond = 9 xx k_2

here {square,diamond} in {0,1,2,3,4,5,6,7,8,9}

From c_1-> diamond in {2,6}

Choosing diamond = 2 we have c_2->6+2+square_1=9 xx k_3
so square_1=1

Choosing diamond = 6 we have c_2->6+6+square_2=9 xx k_4
so square_2 = 6

The solutions are n_1 = 12132 and n_2 = 12636