The word(s) "why" appears 68 time(s) in 63 verse(s) in Quran in Mohsin Khan translation.

(21) And if you do not bring them a miracle [according to their (i.e. Quraish-pagans') proposal], they say: "why have you not brought it?" Say: "I but follow what is revealed to me from my Lord. This (the Qur'an) is nothing but evidence from your Lord, and a guidance and a mercy for a people who believe."

(22) And why should not Allah punish them while they hinder (men) from Al-Masjid-Al-Haram, and they are not its guardians? None can be its guardians except Al-Muttaqun (the pious - See V.2:2), but most of them know not.

(23) May Allah forgive you (O Muhammad صلى الله عليه وسلم). why did you grant them leave (for remaining behind; you should have persisted as regards your order to them to proceed on Jihad ), until those who told the truth were seen by you in a clear light, and you had known the liars?

(24) So perchance you (Muhammad صلى الله عليه و سلم) may give up a part of what is revealed unto you, and that your breast feels straitened for it because they say, "why has not a treasure been sent down unto him, or an angel has come with him?" But you are only a warner. And Allah is a Wakil (Disposer of affairs, Trustee, Guardian) over all things.

(25) They said: "O our father! why do you not trust us with Yusuf (Joseph) though we are indeed his well-wishers?"

(26) And the disbelievers say: "why is not a sign sent down to him from his Lord?" You are only a warner, and to every people there is a guide.

(27) And those who disbelieved say: "why is not a sign sent down to him (Muhammad صلى الله عليه و سلم) from his Lord?" Say: "Verily, Allah sends astray whom He wills and guides unto Himself those who turn to Him in repentance."

(28) "And why should we not put our trust in Allah while He indeed has guided us our ways? And we shall certainly bear with patience all the hurt you may cause us, and in Allah (Alone) let those who trust, put their trust."

(29) "why do you not bring angels to us if you are of the truthful?"

(30) "These our people have taken for worship alihah (gods) other than Him (Allah). why do they not bring for them a clear authority? And who does more wrong than he who invents a lie against Allah.