M001 Chapter 4 db.inspections quiz gave incorrect answer

The quiz query asked for the following;

sample_training> db.inspections.find({ "address.city": "NEW YORK" }).count()
18280

It was marked wrong and the supposed answer was 18279 for the same query?
I had not modified the data set from the original.

What went wrong?

18279 is correct
I think your data got changed
Reload the sample data and try again

I did the exact same query and got 5. I submitted this number but the system said it is wrong. I tried to reload the data and got an error message saying there is not enough free space to load the data. Has the data changed? I know I entered the correct query but got the wrong answer.

Drop all your old dbs and reload the data
If you are not comfortable drop your cluster then create a new one and load the sample data

Is there an easy way to drop all my dbs? I would just go into the Atlas cluster and write a command to drop each collection and then the db one at a time like this: db.inspections.drop(), and then db.zips.drop(). Is that all I have to do? Thanks.

What you have shown is drop a collection
You have to drop the DBs like sample_training etc
do this
show dbs
use db (switch the db you want to drop by replacing db with db_name)
dropDatabase()
drop all sample_xx dbs and any others you have created
Don’t touch admin & local dbs