Answer
$\frac{1}{10}$ of the estate goes to charity.
Work Step by Step
A will notes that $\frac{3}{5}$ of an estate is to be divided among relatives.
If $\frac{3}{5}$ of the estate goes to relatives, then the part of the estate not going to relatives is: 1 - $\frac{3}{5}$ = $\frac{5}{5}$ = $\frac{3}{5}$ = $\frac{2}{5}$.
Now, we know that $\frac{2}{5}$ of the estate will go somewhere other than to relatives. The problem notes that $\frac{1}{4}$ of the estate remaining after the relatives receive their their share is to go to charity. This means that $\frac{1}{4}$ of the remaining $\frac{2}{5}$ goes to charity.
Since "of" is a way to indicate multiplication in word problems, we multiply: $\frac{2}{5}$ x $\frac{1}{4}$ = $\frac{2}{20}$ = $\frac{1}{10}$ (The amount that goes to charity.)