Answer:
the mean of A and C is 10
Step-by-step explanation:
Given;
mean of A and B = 20
mean of B and C = 24
mean of A, B and C = 18
[tex]\frac{A + B}{2} = 20\\\\A+ B = 40 ---- (1)\\\\\frac{B + C}{2} = 24\\\\B+ C = 48----(2)\\\\\frac{A+ B+ C}{3} = 18\\\\A+ B+ C= 54---(3)\\\\From (1); \ A = 40 - B\\\\From(2); \ C = 48 - B\\\\\Substitute \ the \ values \ of \ A \ and \ C \ into \ (3)\\\\(40-B) + B + (48-B) = 54\\\\simplify;\\\\(40 + 48) + (B-B-B)= 54\\\\88 -B = 54\\\\-B = 54-88\\\\-B = -34\\\\B = 34[/tex]
Recall; A = 40 - B
A = 40 - 34
A = 6
Also, C = 48 - B
C = 48 - 34
C = 14
Therefore, the mean of A and C is calculated as;
[tex]= \frac{A + C}{2} \\\\= \frac{6 + 14}{2} \\\\= 10[/tex]
