Răspuns:
Vom nota: L = Liana, P = Petru, T = Tudor
L + P + T = 165 kg
L + P = 100 kg
P + T = 120 kg
T = (L + P +T) - (L + P)
T = 165 kg - 100 kg
T = 65 kg
P + T = 120 kg
P + 65 kg = 120 kg
P = 120 kg - 65 kg
P = 55 kg
L + P = 100 kg
L + 55 kg = 100 kg
L = 100 kg - 55 kg
L = 45 kg
Liana cantareste 45 de kilograme
Petru cantareste 55 de kilograme
Tudor cantareste 65 de kilograme
