Answer:
Step-by-step explanation:
It can help to make a table from the given information. The attached table is filled in from the given values (underlined in green). We know that rows and columns must add to 100%, so the remaining numbers are easily found by subtraction.
a) This is the number in the upper left corner, 9%.
b) This is the sum of the over 18 row (82%) and the number in (a), so is ...
... 82% +9% = 91%.
Alternatively, it is the sum of the male column (51%) and the over 18 female number (40%):
... 51% +40% = 91%.
It is also the complement of the number in (c).
c) This is the number in the upper center box, 9%.
It is also the complement of the number in (b).