1. Although SQL is case insensitive our database is case sensitive. So you 
may type "SELECT" or "select" and it will not make any difference but when 
you check for example if the city is Glasgow, writing 'glasgow' instead of 
'Glasgow' makes a difference. So the values saved in the db are case 
sensitive.

2. The result of the 2nd question is the empty table ("no rows selected").  

3. The result to the 4th question is the empty table ("no rows selected").

4. By saying "the maximum number of rooms a flat has in each city" I mean 
that if there are two flats in Glasgow and one of them has 3 rooms while 
the other has 6 rooms the result should be

City     # of flats    maximum # of rooms
Glasgow      2              6

5. Change question 10 to
"In which branches the minimum salary is less than 10000?"