Secondly, what, which, how many and mow much also become subjects of the sentence. In this case we don't use an auxiliary verb like other positive sentence. The only difference between these two are with other subjects a sentence is positive having the positive sense or meaning but with what, which, how many and mow much the sentence is still positive but has an interrogative sense or meaning and therefore has a question mark at the end.
E.g. How many people arrived? = Ten people arrived. (No auxiliary verb needed)
What makes you laugh? = Ali makes you laugh. (No auxiliary verb needed)
Hope this helps.