Competition problem — Combinatorics

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Combinatorics Difficulty 5.0 AIME Find the answer

34. From the 20 natural numbers 1 to 20, the Pokémon chooses several numbers (at least two) such that the last digit of their product is 3. The total number of different ways to do this is $\qquad$ .

Your answer

A number or a short expression. Spacing and $ signs are ignored.

Solution

$62$

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Source: NuminaMath-1.5, licensed Apache-2.0. Statement and solution reproduced as published; topic and difficulty added by this site.