Np class of problems

Question

Are All problems in NP are known to be reducible to one another. I know if a problem X is in NP and any NP problem Y in NP is reducible to X then X is NP-complete. So by this assumption can we state that all NP problems are reducible to one another?

Answer 1

A decision problem C is NP-complete if:

C is in NP, and
Every problem in NP is reducible to C in polynomial time. 

Source: https://en.wikipedia.org/wiki/NP-completeness

If all NP problems are reducible to one another, it would mean that all NP problems are NP complete, which we can not say since we still can't prove whether P = NP Refer to the image below for a better understanding.