An online newspaper had listed 100 visitors in October. The number of visitors in November increased by 15%. There were 15 more visitors in December than in November. What is the total number of visitors for these three months? Let's answer step by step:
There was an increase of 100 x 15 / 100 = 15 visitors in November. So, the number of visitors in November was 100 + 15 = 115. In December, the number of visitors was 115 + 15 = 130. Therefore, a total of 100 + 115 + 130 = 345 visitors listed in these three months. The answer: 345.