# SAT/ACT problem of the week, October 06, 2016 solution

Hints for problem of elimination: You might get an intuitive feeling that 1 and 3 are too small, leaving you with three choices. Even if you don’t know the full answer, you must guess at this point.

Read on for a full solution.

# SAT/ACT problem of the week, October 06, 2016

An integer $latex x$ has $latex n$ zeros at the end if and only if it is divisible by $latex 10^n$. For example, 12,500,000 is divisible by $latex 10^5$ but not by $latex 10^6$.

How many zeros are at the end of $latex 1 \times 2 \times 3 \times \cdots \times 100$?

Solutions, hints, and questions are welcomed. A full solution will be posted on October 12th. If you would like to learn how to enter math formulas into this blog, visit the WordPress LaTeX tutorial page.

# SAT problem of the week, October 06, 2014 solution

Hints for problem of elimination: You might get an intuitive feeling that 1 and 3 are too small, leaving you with three choices. Even if you don’t know the full answer, you must guess at this point.

Read on for a full solution.

An integer $latex x$ has $latex n$ zeros at the end if and only if it is divisible by $latex 10^n$. For example, 12,500,000 is divisible by $latex 10^5$ but not by $latex 10^6$.
How many zeros are at the end of $latex 1 \times 2 \times 3 \times \cdots \times 100$?