You chose 10 points. This is the correct answer. You got 9 points for your honour cards, and one point for having a doubleton. You do not get any points for long suits, because none of your suits has more than 4 cards in it. Well done.
5. Now with the same hand as before, what will you bid?
Spades
A,K,3
Hearts
10,9,8,7
Diamonds
8,4
Clubs
Q,9,6,4