On the first day of a measles outbreak at a school, 5 students were identified to have the measles. each day for the following two weeks, the number of new cases doubled from those identified with the disease the day prior.

how many students are identified to have measles in all at the end of the 6th day of the outbreak?

286

315

345

378

If you interpret the question as is, the answer is in the thousands, which is not listed. The last part of the question should read 'the number of new cases doubled from those newly identified cases from the day prior. The question is very poorly phrased.

Day 1 : 5
Day 2: 5 + 10
Day 3: 15 + 20
Day 4: 35 + 40
Day 5: 75 + 80
Day 6: 155 + 160

Which is 315 at the end of 6th day