From the 200 cookies, Javier's wife ate 30/100*200 = <<30/100*200=60>>60
After the wife ate 60 cookies, the number of cookies that remained was 200-60 = <<200-60=140>>140
The daughter also ate 40 cookies leaving 140-40 = <<140-40=100>>100 cookies.
If Javier ate half of the remaining cookies, he ate 1/2*100 = 50.
The number of cookies that remained is 100-50 = <<100-50=50>>50
#### 50