Answer: Mean of the other numbers = 9
====================================================
Step-by-step explanation:
We have 6 numbers total we're working with
S = sum of the all six numbers
m = mean of the all six numbers = 10
m = S/6
6m = S
S = 6m
S = 6*10
S = 60
All six numbers add to 60.
-----------
T = sum of two of the numbers
n = mean of two of the numbers = 12
n = T/2
T = 2n
T = 2*12
T = 24
Two of the numbers add to 24.
-----------
U = sum of the other four values
p = mean of the other four values
p = U/4
U = 4p
The other four values add to 4p
------------
We found that the first two items add to 24, and the remaining 4 items add to 4p. The grand total sum is 24+4p or 4p+24.
In the first section, we found that all six items add to S = 60
So,
4p+24 = 60
4p = 60-24
4p = 36
p = 36/4
p = 9
The mean of the other four numbers is 9.