Question

Trei numere au suma 74.Media aritmetica a primelor doua este 21,iar media aritmetica a ultimelor doua este 28 ..Aflati cele trei numere !

Answer 1

a+b+c=74
($\frac{a+b}{2}$)=21 a+b=42
($\frac{b+c}{2}$)=28 b+c=56
1.42+c=74
c=32
2.a+56=74
a=18
3.32+18+b=74
b=74-50
b=24

Answer 2

a + b + c = 74
Ma = ( a + b ) : 2 = 21 = > a + b = 21 x 2 = > a + b = 42
= > c = 74 - 42 = > c = 32
Ma = ( b + 32 ) : 2 = 28 = > b + 32 = 2 x 28 = > b + 32 = 56 = > b = 56 - 32 = > b = 24
a + 24 = 42 = > a = 42 - 24 = > a = 18