# Composing 30

**Discrete Mathematics**Level 3

How many ways can the number \(30\) be written as an ordered sum of 2s and 5s?

**Details and assumptions**

There are four ways to write 12 as an ordered sum: \(2+2+2+2+2+2=12,\) \(2 + 5 + 5 = 12,\) \(5 + 2 + 5 = 12\), and \( 2 + 5 + 5 = 12 \). The ordered sum can use 0 5's, and it can also use 0 2's.