I got a 12 discount on a pair of jeans and a 25% discount on a t-shirt the original price of the jeans was $100 and thatof the T-shirt $50, how much did i pay for both items? (NEED EQUATION AND WORK)

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?