Think of it this way.  Read them all and you'll see it and
understand it:

1. A financial advisor has invested $8000 into 2 accounts.
If one account contains $1000 dollars the amount in the 
second amount is gotten but subtracting $8000-$1000,
WHICH WORKS OUT TO BE $7000.

2. A financial advisor has invested $8000 into 2 accounts.
If one account contains $2000 dollars the amount in the 
second amount is gotten but subtracting $8000-$2000,
WHICH WORKS OUT TO BE $6000.

3. A financial advisor has invested $8000 into 2 accounts.
If one account contains $3000 dollars the amount in the 
second amount is gotten but subtracting $8000-$3000,
which would work out to be $5000. 

4. A financial advisor has invested $8000 into 2 accounts.
If one account contains $4000 dollars the amount in the 
second amount is gotten but subtracting $8000-$4000,
WHICH WORKS OUT TO BE $4000.

5. A financial advisor has invested $8000 into 2 accounts.
If one account contains $5000 dollars the amount in the 
second amount is gotten but subtracting $8000-$5000,
WHICH WORKS OUT TO BE $3000.

6. A financial advisor has invested $8000 into 2 accounts.
If one account contains $6000 dollars the amount in the 
second amount is gotten but subtracting $8000-$6000,
WHICH WORKS OUT TO BE $2000.

6. A financial advisor has invested $8000 into 2 accounts.
If one account contains $7000 dollars the amount in the 
second amount is gotten but subtracting $8000-$7000,
WHICH WORKS OUT TO BE $1000.

Now after reading all those, read this:

8. A financial advisor has invested $8000 into 2 accounts.
If one account contains $X dollars the amount in the 
second amount is gotten but subtracting $8000-$X,
BUT YOU CAN'T WORK THAT OUT BECAUSE THERE ARE UNLIKE TERMS,
SO ALL YOU CAN DO IS LEAVE IT 8000-X dollars!

That's the answer!!!

Edwin