3) 3 h si 60 s
1h=60min si 1min=60 s
180min+1min=181 min
2,5h si 240 s
2,5h=2,5*60=150 min
240 s=240s*60s=14400min
14400min+1150min=14550min
1 si 1/2 h si 780 s
1 1/2=3/2=1,5h=90 min
780s=780s*60s=46800min
46800min+90min=46890min
4)a) 10 h 48 min 32 s+8 h 30 min 48 s=
Acum adunam h cu h min cu min ,s cu s
42 h 78 min 80 s
b) 3 h 12 min 36 s+2 h 18 min 33 s=5 h 30 min 69 s
c)3 1/2 h 38 min 40 s+3,5 h 21 min 20 s=
3 1/2 =7/2 h=3,5 h
3,5 h 38 min 40 s +3,5 h 21 min 20 s=7 h 59 min 60 s
5) a) 9 h 3 min-6 h 57 min =2 h 73 min
b) 20 min 35 s- 12 min 47 s= 7 min 88 s
c) 11 h 37 min 24 s-8 h 47 min 38 s=2 h 89 min 86 s
6) 1 zi =24 h
360 zile=? h
360 zile *24 h=8640 h
