total elevi
|____|____|____|____|
clasa a 4-a
|____|
rest1 |____|____|____|
clasa a 3-a
|____|____|
rest2 |____| 15 elevi clasa intai
2×15 = 30 elevi ( clasa a 3-a)
15 elevi clasa a 4-a
15×4 = 60 elevi ( in total)
Verificare:
15+30+15 = 60
In excursie pleaca 60 de elevi.