MathDB

1

Part of 2014 ITAMO

Problems(1)

Eliminate zeroes from n: ITAMO 2014 P1

Source:

11/19/2014
For every 33-digit natural number nn (leading digit of nn is nonzero), we consider the number n0n_0 obtained from nn eliminating all possible digits that are zero. For example, if n=207n = 207, then n0=27n_0 = 27. Determine the number of three-digit positive integers nn, for which n0n_0 is a divisor of nn different from nn.