Hristos a Inviat!
7)
Fie numerele a, b, c. Avem:
(a+b+c)/3 = 6
(a+b)/2 = 5
(b+c)/2 = 7
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a,b,c =?
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(a+b+c)/3 = 6 => a+b+c = 18
(a+b)/2 = 5 => a+b = 10
(b+c)/2 = 7 => b+c = 14
a + b + c - (a+b) = 18 - 10 = 8 = c
b+c = 14 => b + 8 = 14 => b = 6
a + b = 10 => a + 6 = 10 => a = 4
8)
(a+b+c+d)/4 = 1,75 => a+b+c+d = 4 x 1,75 = 7
(e+f+g+h+i+j)/6 = 2,5 => e+f+g+h+i+j = 6 x 2,5 = 15
Deci
(a+b+c+d+e+f+g+h+i+j)/10 = (7+15)/10 = 22/10 = 2,2