SOLUTION: The average (arithmetic mean) of r, s, x and y is 8, and the average of x and y is 4. what is the average of r and s? a)4 b) 6 c) 8 d) 12

Algebra ->  Test -> SOLUTION: The average (arithmetic mean) of r, s, x and y is 8, and the average of x and y is 4. what is the average of r and s? a)4 b) 6 c) 8 d) 12       Log On


   

Question 782492: The average (arithmetic mean) of r, s, x and y is 8, and the average of x and y is 4. what is the average of r and s?
a)4
b) 6
c) 8
d) 12
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
The average (arithmetic mean) of r, s, x and y is 8,
%28r%2Bs%2Bx%2By%29%2F4=8
r%2Bs%2Bx%2By=32.......eq.1
and the average of x and y is 4
%28x%2By%29%2F2=4
%28x%2By%29=8.....eq.2..substitute in eq.1
r%2Bs%2B%28x%2By%29=32.......eq.1
r%2Bs%2B%288%29=32
r%2Bs+=32-8
r%2Bs+=24
the arithmetic mean will be %28r%2Bs%29%2F2+=12
so, your answer is d) 12