MySQL: Retrieve data from Parent Table if it's Child Table's sum of QtyIn is greater than the sum of QtyOut

Question

Here\'s my scenario:

Table A     Table B 
IDa = 1     IDb = 1 | IDa = 1 | QtyIn = 2 | QtyOut = 0
IDa = 2     IDb = 2 | IDa = 1 | QTyIn = 0 | QtyOut = 1