Student or Learner
This type of questions is/are quite common.
Should it be 'is' or 'are'?
The subject in each of the sentences is "type".
The "of questions" is a prepositional phrase - used as an adjective describing the subject "type".
This type is common.
These types are common.
Sometimes it helps to remove extraneous phrases and words when looking at subject/verb agreement issues.
Don't get Svartnik started on notional agreement, or we'll be here all night, and I have some serieous catching up to do tonight! Sevilla! Ah!
I like the clarity of Bhaisahab's suggestions.