The Air Up There Flying Fungi

 Question: We tested the air in your classroom and found 7 different kinds of mould. Eek! The cleaner says that it takes 5 days for each mould to be eradicated (removed). If the school had to remove each mould one at a time, how long would it take to remove all the mould from the classroom?

So if it takes 5 days for one type of fungi to be removed all we need to do is 7 X 5 which equals 35 so the answer must be 1 month and 4 days if it were in a month with 31 days or it could be 1 month and 5 days if it were in a month with 30 days, or it could be 1 month and 7 days if it were in a month with 28 days.

So that's how I worked out the answer.