The average of six numbers is 6. If 3 is subtracted from each of four of the numbers, what is the new average?

Nice answer, ND........here's my slightly different approach......

Let the sum of the six numbers = S

So

S/6 = 6

And if 3 is subtracted from each of four numbers, we have...

(S -12) / 6 =

S/6 - 12/6 =

6 - 2   = 4

The average of 6 numbers is 6. This means that all 6 numbers have to add up to 36.

It doesn't matter what the numbers are, but in order to average out to 6, the sum of all the numbers divided by 6 has to equal 6.

The only thing that gives 6 when divided by 6 is 36.

Now, 3 is subtracted from 4 numbers, for a total of 12.

(36-12)/6 tells us our new average

24/6

4 is the new average.

Thanks NinjaDevo!

Anytime!                  

You have given an excellent answer Ninja.  

Perhaps you would like to include it in your new sample questions thread.