Someone draws a 2400 franc annuity 8 times at the end of every third year, what is the present value of the annuity at $4 \%$?
The current value of the annuity

$$
t=\frac{2400}{e^{3}}+\frac{2400}{e^{6}}+\ldots+\frac{2400}{e^{24}}
$$

which simplifies to

$$
t=\frac{2400}{e^{24}} \cdot \frac{e^{24-1}}{e^{3}-1}
$$

Upon calculation, $t=11723$ forints.

(Miksa Roth.)

The problem was solved by: Barna D., Beck F., Bojedain F., Détshy K., Fekete J., Kallos M., Schiffer H., Szabó I., Weisz J.