2h+210 minute + 3 supra 4 h =2 h+3h 30 min+45 min=5 h 75 min =6h 15 min
210 min = 3 h 30 min
3/4 h × 60 min/h=45 min
75 min= 1 h 15 min
2)
a) 8151 de secunde = 2 h 15 min 51 sec
8151 sec : 3600 sec/ora=2 ore rest 951 sec.
951 sec.:60 sec/min=15 min si rest 51 sec
b) 15300 de secunde=4 h 15 min
15300 sec : 3600 sec/ora=4 ore rest 900 sec.
900 sec.:60 sec/min=15 min
