Annie learned that on day 1 of the outbreak, there were 105 infected dogs, and on day 2, there were 120 infected dogs. She noticed that each day, 15 more dogs became infected.

Annie used these numbers to set up an alternative model calculating the spread of disease, and wanted to use it to predict when the disease would infect 300 dogs.

According to Annie's alternative model, after how many days will the number of infected dogs reach 300?

2 answers

300 = 15 d + 105
This problem is an Arithmetic sequence