Răspuns :
r - nr masini rosii
n - nr masini negre
a - nr masini albe
r + n = 38
a + n = 25
r + n + a = 63
r + 25 = 63 => r = 38 => n = 0 => a = 25
Intr-adevar nu exista nicio masina de culoare neagra.
n - nr masini negre
a - nr masini albe
r + n = 38
a + n = 25
r + n + a = 63
r + 25 = 63 => r = 38 => n = 0 => a = 25
Intr-adevar nu exista nicio masina de culoare neagra.
R+N+A=63;
R+N=38;
A+N=25;
⇒A=[R+N+A]-[R+N]
⇒A=63-38
⇒A=25[masini-albe];
⇒N=[A+N]-A
⇒N=25-25
⇒N=0[masini negre]⇒nu exista o culoare[negru];
⇒R=[R+N]-N
⇒R=38-0
⇒R=38[masini-rosii];
R+N=38;
A+N=25;
⇒A=[R+N+A]-[R+N]
⇒A=63-38
⇒A=25[masini-albe];
⇒N=[A+N]-A
⇒N=25-25
⇒N=0[masini negre]⇒nu exista o culoare[negru];
⇒R=[R+N]-N
⇒R=38-0
⇒R=38[masini-rosii];