A ship sails from Catania (north latitude $b=37^{\circ} 30^{\prime}$, longitude from Paris $l=12^{\circ} 40^{\prime}$) to Alexandria by the shortest route (north latitude $b_{1}=31^{\circ} 30^{\prime}$, longitude $l_{1}=33^{\circ} 8^{\prime}$); how long did it take to complete this journey if the ship traveled at a speed of $18 \frac{1}{2} \mathrm{~km}-\mathrm{t}$ per hour.
The essence of the task essentially matches problem 991, except that instead of the 15-hour difference, we need to use the difference in longitudes, \( l_{1} - l = 20^{\circ} 28' \). The distance traveled by the ship is \( 1987.5 \, \text{km} \), and the sought time is 4 days 11 hours 25 minutes.

(Losonczy István, Fiume.)

The problem was also solved by: Bartók I., Enyedi B., Liebner A., Rássy P., Riesz K.