Gina's mom received 1/4 x $400 = $<<1/4*400=100>>100.
She used 1/8 x $400 = $<<1/8*400=50>>50 to buy clothes.
She gave 1/5 x $400 = $<<1/5*400=80>>80 to a charity.
Thus, she spent a total of $100 + $50 + $80 = $<<100+50+80=230>>230.
Therefore, Gina kept $400 - $230 = $<<400-230=170>>170.
#### 170