I need help solving this equation!

In the rectangle below ac=30 units what is de

Abby is preparing fruit punch for her party. she starts with a bowl filled with liquid that has 1/2 fruit juice and 1/2 sprite, but she decides it's too fruity. so she pours out 1/4 of the liquid, and then fills the bowl up again with sprite. what fraction of the punch is now sprite?

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)