5. (5 points) $A$, $B$, and $C$ are three fractions, where both the numerators and denominators are natural numbers. The ratio of the numerators is $3: 2: 1$, and the ratio of the denominators is $2: 3: 4$. The sum of the three fractions is $\frac{29}{60}$. Then, $A-B-C=$ $\qquad$ .
【Solution】Solution: The ratio of the fractional values is $(3 \div 2):(2 \div 3):(1 \div 4)=18: 8: 3$,
$$
\begin{array}{l}
\frac{29}{60} \times \frac{18-8-3}{18+8+3} \\
=\frac{29}{60} \times \frac{7}{29} \\
=\frac{7}{60}
\end{array}
$$