The electronic configuration of an element ,X , is represented by 1s2 2s2 2p6 3s2 3p6 3p6 4s2 and 3d3. Determine the atomic number of X

Answer 1

just count the number of electrons

the 1st number is the orbital ... the following letter is the suborbital (s, p, d)

the last number is the number of electrons in the suborbital
... add all these numbers

Answer 2

This can't be. You have typed two 3p6 levels and no two electrons can have the same quantum numbers in an atom. Either you have made a typo or the author of the problem has made an error. You can't have two 3p6 levels in the same element. This question, as posted, has no correct answer.