At a game, Selena, Rihanna and Tina had a total of 320 clips. Selena had the least number of clips. The ratio of Rihanna’s clips to Tina’s clips was 5:4 at first. After Selena and Rihanna had each lost 1/2 of their clips, Rihanna had 50 clips more than Selena. The girls had a total of 220 clips in the end.

a) What is the ratio of the number of Rihanna’s clips to the number of Tina’s clips at the end of the game?

b) How many clips did Selena have at first?