Hello!
There are different ways to write a mixed number as a decimal.
I'll explain to you how to do it using the division of the fraction, look:
We have the number 3 3/5.
First, notice that 3 is a whole number, so we will ignore it now. Let's work with this fraction 3/5.
Let's do the division between 3 and 5, look:
Notice that 3/5 = 0.6
Do you remember the whole number that we ignored before? Now we will add this result of the fraction with that number, look:
[tex]\begin{gathered} 3+0.6=3.6 \\ \\ 3\frac{3}{5}=3.6 \end{gathered}[/tex]So, 3 3/5 as a decimal is 3.6.