1 grad = 60 minute
1 minut = 60 secunde
a) 12 grade 15 minute = (12x60) minute + 15 minute = (720+15) minute = 735 minute = (735x60) secunde = 44100 secunde
b) 20 grade 30 minute = (20x60) minute + 30 minute = (1200 + 30) minute = 1230 minute = (1230x60) secunde = 73800 secunde