During a collection, a seven-member group each donated 10 forints per person. The seventh person donated 3 forints more than the average donation of the 7 people. How much did the seventh person donate?
I. solution: Let the total amount of donations be $x \mathrm{Ft}$, then according to the problem

$$
x=60+\frac{x}{7}+3
$$

from which

$$
6 x=441, \quad \text { and thus } \quad x=73.5 .
$$

Therefore, the donation of the seventh person was $73.5-60=13.5 \mathrm{Ft}$.

Zahumenszky Zille (Bp. VIII., Fazekas g. I. o. t.)

II. solution: Let the donation of the seventh person be $x \mathrm{Ft}$, then

$$
\frac{60+x}{7}=x-3, \quad \text { from which } \quad x=13.5 \mathrm{Ft} .
$$

Dulovics Emilia (Bp. VIII., Fazekas g. I. o. t.)

III. solution: The seventh person donated $3 \mathrm{Ft}$ more than the average, and this $3 \mathrm{Ft}$ increases the average of the other 6 people. Thus, the average of their donations is $10+\frac{3}{6}=10.5 \mathrm{Ft}$. Therefore, the seventh person donated $10.5+3=13.5 \mathrm{Ft}$.

Ágh Attila (Bp. V., Eötvös J. g. II. o. t.)