Maths Olympiad Prep

Track / Stage 4 / 322 of 340 #582 of 1964

Problem 582

AMC 12 late, AIME early
Number theory Difficulty 5.0 Find the answer

8. Among the following four numbers 13076743680001307674368000, 13076743685001307674368500, 13076743682001307674368200, 13076743680101307674368010, only one is the product of the integers from 1 to 15. This number is ( ). Note: Comprehensive application of divisibility

A number or a short expression. Spacing, $ signs and \frac vs / are all fine.

Official solution

【Analysis】Observation shows that among the four numbers above, only the last three digits are different.
In 15! : the number of 2s is 11; the number of 5s is 3, so there must be 3 zeros at the end, making this number 1307674368000

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