Nikka has a 100 stamp collection. Thirty-five percent of her stamps are Chinese, 20% are US stamps, and the rest are Japanese stamps. How many Japanese stamps does Nikka have? Let's answer step by step:
Nikka has 100 x 35 / 100 = 35 Chinese stamps. She has 100 x 20 / 100 = 20 US stamps. So, Nikka has 35 + 20 = 55 stamps that are not Japanese. Thus, Nikka has 100 - 55 = 45 Japanese stamps. The answer: 45.