the average (arithmetic mean) of a and b is 10, whereas the average of b and 10 is c/2. What is the average of a and c.
2007-01-31 11:51:11 · 4 answers · asked by Acewall 1 in Science & Mathematics ➔ Mathematics
(a+c)/2 = average of a & c
For that matter, the average of any two numbers are those numbers added to each other divided by 2/
2007-01-31 12:06:48 · answer #1 · answered by Anonymous · 0⤊ 0⤋
I got 15.
If the average of a & b is 10, then a + b divided by 2 equals 10. Solve for a. a= -b + 20.
b + 10 divided by 2 equals is c/2. solve for c. c= b + 10.
Now add a + c and divide by two.
You end up with 30/2 or 15.
2007-01-31 20:07:49 · answer #2 · answered by Reese's Pieces 2 · 0⤊ 0⤋
If you put these words into an equation you will get the equations
(a+b)/2=10
(b+10)/2=C/2
Then we can multiply both equations by two in order to get
a+b=20
b+10=c
Then we solve for b in the first equation getting
b=20-a
Then we substitute for the b into the second equation yielding
20-a+10=c
Let's combine like turns and arrive at the equation
30=c+a
From this we know that the the sum of the two numbers is thirty, and since there are two numbers we divide the sum in half to find the half getting the number 15.
2007-01-31 20:38:50 · answer #3 · answered by brads 2 · 0⤊ 0⤋
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2007-01-31 19:59:27 · answer #4 · answered by Cutie 4 · 1⤊ 0⤋