Răspuns :
(a+b+c)/3=140
a+b+c=420
a=c/4
(a+b)/2=90
a+b=180
180+c=420
c=240
a=240:4=60
b=180-60=120
nr sunt 60, 120 si 240
a+b+c=420
a=c/4
(a+b)/2=90
a+b=180
180+c=420
c=240
a=240:4=60
b=180-60=120
nr sunt 60, 120 si 240
[a+b+c]/3=140
a+b+c=3·140
a+b+c=420;
[a+b]/2=90
a+b=2·90
a+b=180;
⇒c=[a+b+c]-[a+b]
⇒c=420-180
⇒c=240;
⇒a=240/3
⇒a=80;
⇒b=[a+b]-a
⇒b=180-80
⇒b=100;
a+b+c=3·140
a+b+c=420;
[a+b]/2=90
a+b=2·90
a+b=180;
⇒c=[a+b+c]-[a+b]
⇒c=420-180
⇒c=240;
⇒a=240/3
⇒a=80;
⇒b=[a+b]-a
⇒b=180-80
⇒b=100;