PLEASE CAN SOMEONE HELP ME

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?

The difference of three and the reciprocal of a number is equal to the quotient of 20 and the number. find the number.

Fast! find the length of cu. the triangles are similar. show your work.