Answered

A, B and C stand for 3 different numbers.
The mean of A and B is 40.
The mean of B and C is 35

A+B+ C

Calculate ALL their values.



Answer :

ZackFry
The mean is x amount of numbers added together divided by x. Since both mean questions have only 2 numbers, you times 40 and 35 by 2 to reverse the question. 

40 X 2 = 80 = a + b. 
35 X 2 = 70 = b + c. 
100 = a + b + c

80 and 70 are quite close together.  Therefore, b would probably be around 40 - 60.  I used trial and error to work out the answer. 

b = 40
80 - 40 = 40.  
a = 40. 
70 - 40 = 30. 
c = 30. 
40 + 40 + 30 = 110. 
THIS ANSWER IS WRONG. 

b = 50. 
80 - 50 = 30. 
a = 30. 
70 - 50  = 20.
c = 20. 
50 + 30 + 20 = 100. 
THIS ANSWER IS CORRECT. 

a = 30
b = 50
c = 20
olemakpadu
Mean of A & B :    (A+B)/2 = 40.  Cross multiply
A + B = 80.

Mean of B & C:      (B+C)/2 = 35.  Cross multiply
B + C = 70.

(A + B + C) = 100        Note A + B = 80.

Therefore C  = 100 - (A+B) = 100 - 80 = 20.
C = 20.

A = 100 - (B+C) = 100 - 70 = 30.
A = 30.

A + B = 80
30 + B = 80
B = 80 -30 = 50.

A = 30, B = 50, C = 20.

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