Răspuns :
1.15*4=60
60*2=120
120*4=480
VERIFICARE:
480:4=120:2=60:4=15
2.,12*2=24
24*3=72
NR=72
VERIFICARE:
72:3=24
24:2=12
60*2=120
120*4=480
VERIFICARE:
480:4=120:2=60:4=15
2.,12*2=24
24*3=72
NR=72
VERIFICARE:
72:3=24
24:2=12