Queries within a Query question

[Darren \(at work\)]

Hi,

I am trying to work out the following equation:

----------------------------------------------------------------------------
Attrition Rate = ((Production Faults - faults verified)/Production Qty)*100
----------------------------------------------------------------------------

SQL for 'Production Faults' =
--------------------------
SELECT Inspection.Partcode, (Count(*)/[Production Input]) AS Fault_Rate
FROM Inspection
WHERE (((Inspection.Date) Between [Enter first date] And [Enter second
date]) AND ((Inspection.Prod_Rej)=True))
GROUP BY Inspection.Partcode, Inspection.QA_Result
HAVING (((Inspection.Partcode)=[Enter PartCode]) AND
((Inspection.QA_Result)="P1" Or (Inspection.QA_Result)="P2"));
-------------------------

SQL for 'faults verified' =
-------------------------
SELECT Inspection.Partcode, (Count(*)/[Production Input]) AS Faults_Verified
FROM Inspection
WHERE (((Inspection.Date) Between [Enter first date] And [Enter second
date]) AND ((Inspection.Prod_Rej)=True) AND ((Inspection.QA_Result)="Pass"
Or (Inspection.QA_Result)="Retouched"))
GROUP BY Inspection.Partcode
HAVING (((Inspection.Partcode)=[Enter PartCode]));
-------------------------

Both these queries work individually as intended.
My question is how do I combine these two queries to give me the results as
specified in the initial equation?
What I have tried so far is far from being pretty, and does not give the
correct result. I was hoping someone could cast a fresh, and more
experienced set of eyes over what I have so far and give a helping hand?

Final query so far: ( I said it wasn't pretty )
----------------------------
SELECT Inspection.Partcode, ((
SELECT Count(*) AS ProdFaults
FROM Inspection
WHERE (((Inspection.Date) Between [Enter first date] And [Enter second
date]) AND ((Inspection.Prod_Rej)=True))
GROUP BY Inspection.Partcode
HAVING (((Inspection.Partcode)=[Enter PartCode]))
)
-
((
SELECT Count(*) AS ProdfaultsMinus
FROM Inspection
WHERE (((Inspection.Date) Between [Enter first date] And [Enter second
date]) AND ((Inspection.Prod_Rej)=True))
GROUP BY Inspection.Partcode, Inspection.QA_Result
HAVING (((Inspection.Partcode)=[Enter PartCode]) AND
((Inspection.QA_Result)="Pass" Or (Inspection.QA_Result)="Retouched"))
))
/
[Production Input]) AS Attrition_Rate
FROM Inspection
WHERE (((Inspection.Date) Between [Enter first date] And [Enter second
date]) AND ((Inspection.Prod_Rej)=True) AND ((Inspection.QA_Result)="Pass"
Or (Inspection.QA_Result)="Retouched"))
GROUP BY Inspection.Partcode
HAVING (((Inspection.Partcode)=[Enter PartCode]));