Paige has 100 space stickers that she is dividing among 3 friends, so 100 stickers / 3 friends = 33 stickers for each friend, with 1 remaining.
She also has 50 cat stickers that she is diving among 3 friends, so 50 stickers / 3 friends = 16 stickers for each friend, with 2 remaining.
So Paige will have 1 remaining space sticker + 2 remaining cat stickers = <<1+2=3>>3 stickers left.
#### 3