How can I reset my security questions answers??

If you have a rescue email address (which is not the same thing as an alternate 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 then see if the instructions on this user tip helps : https://discussions.apple.com/docs/DOC-4551

If you don't currently have a rescue email address set up on your account then you won't get that option - you will need to try what is in the user tip that I linked to

How can i change my rescue email

and can i reset the security questions i for got the answers

How can i change my rescue email

You can't if you've forgotten your answers

Use the 'If you can't reset your security questions' section at the bottom of this page, and contact Support in the country where you are (and which is therefore the country on your iTunes account) : If you forgot the answers to your Apple ID security questions - Apple Support

If your country isn't on that 'call us for help' link : https://www.apple.com/emea/support/itunes/contact.html