If you have a rescue email address set up on your account then you can try going to https://appleid.apple.com/ and click 'Manage your Apple ID' on the right-hand side of that page and log into your account. Then click on 'Password and Security' on the left-hand side of that page and on the right-hand side you might see an option to send security question reset info to your rescue email address.
If you don't have a rescue email address set up then go to Express Lane and select 'iTunes' from the list of 'products' in the middle of the screen.
Then select 'iTunes Store', and on the next screen select 'Account Management'
Next choose 'iTunes Store Account Questions' or 'iTunes Store account security' (it appears to vary by country) and fill in that you'd like your security questions/answers reset.
You should get an email reply within about 24 hours (and check your Spam folder as well as your Inbox).
Or you could see if the second half of Kappy's reply in this thread helps : https://discussions.apple.com/message/20357006#20357006
If you've just added an address then it will be an alternate email address, not a rescue email address - you can only add a rescue email address by answering the 2 questions as shown on your screenshot.
You will need to contact iTunes Support or Apple to get the questions reset.
e.g. you can try contacting iTunes Support : http://www.apple.com/support/itunes/contact/ - click on Contact iTunes Store Support on the right-hand side of the page, then Account Management , and then 'Forgotten Apple ID security questions'
or try ringing Apple in your country and ask to talk to the Accounts Security Team : http://support.apple.com/kb/HE57