Update Qualififaction level Feild on lead

Hello All

I have requirment to update the Qualification level based upon the Answers submited in Survey.Standard functionality will not help as we have more than 40 Questions in Survery and calucating percnetage is not easy.

My requirment is :

Scenario 1: If any one of the Answers selected which as Rating 3 then updated Qualification Level to Not accepted.

Scenario 2: If any of the Qualification Level is answered with Comment and No Answers was selected which as Ratings 3 then updated the Qualification level to Review

Scenario 3. If any one of the Answer is selected which as Rating 2 and No Answers was selected which Ratings 3 then updated the Qualification level to Review

Scenario 4: If all the Answers are selected which as Rating 1 then updated the Qualification Level to 1

Note I want to read only answers rating and Update the Qual level Value,

please guide me how I can acheive this.

Thanks.