Answer:
the proportion of people who are sick after two weeks is 33.2%
Step-by-step explanation:
Given the data in the question;
Let there be 100 people in the city;
20% of them are sick( 20/100 × 100) = 20 people
so 80% are fine = ( 100 - 20 ) = 80
after one​ week, 40% of the people who were sick are still sick
40/100 × 20 = 8%
of the 80% of people who were well, 30% got sick after one week
30/100 × 80 = 24%
so after one week. 8% + 24% = 32% of the people were sick,
hence 68% are fine.
now, after second week 40% of sick and 30% of not sick people previously will be sick
∴ Total people who are sick after two weeks  Â
⇒ 40/100 × 32 + 30/100 × 68
= 12.8 + 20.4
= 33.2
Therefore, the proportion of people who are sick after two weeks is 33.2%