Question

if the mean of a and b is 20 the mean of b and c is 24 and the mean of a,b and c is 18 .what is the mean of a and c

Answer 1

Step-by-step explanation:

you know already:

(a+b)/2 = 60. Rewriting yields a+b = 120 and thus b = 120-a

(b+c)/2 = 72. Rewriting: b+c = 144, c = 144-b = 144-(120-a) = 24+a

(a+b+c)/3 = 54. Now express b and c in terms of a as found above:

a+b+c = 162 [math]\iff[/math] a+120-a+24+a = 162 [math]\iff[/math] 144+a = 162 [math]\iff[/math] a = 18.

So b = 120–18 = 102 and c = a+24 = 18+24 = 42

Now we can compute the mean of a and c: (a+c)/2 = (18+42)/2=30.

Answer 2

Answer:

A+B=20x2=40

B+C=24x2=48

A+B+C=18x3=54

40+C=54, C=14

A+48=54, A=6

A+C/2=10