Question

The flu is spreading in your school. Originally, three people are infected with the flu. Every day, the number of people infected doubles. How many people will be infected on day 9?

A. 768
B. 1536
C. 3072
D. 6144

Answer 1

On day 9, there will be 1536 people infected with the flu.

Step-by-step explanation:

The number of people infected with the flu doubles every day, starting with 3 infected people. So, on day 2, there will be 2 x 3 = 6 infected people. On day 3, there will be 2 x 6 = 12 infected people. Similarly, on day 4, there will be 2 x 12 = 24 infected people.

We can observe that the number of infected people doubles each day. So on day 9, we can calculate the number of infected people as 2^(9-1) x 3 = 1536.

Therefore, the answer is B. 1536.