(100,000*.75)* 8 - 75000*2*4 = 0; 100,000*.75*10 = 750,000
Poor man's math.
Assuming she earns $100,000 , taking home $75,000, two kids going to a college costing $75000 each for four years and further assuming that she will be working for 18 more years.
Disclaimer... Assumption is the mother of all fxxx ups