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

(31) When he said to his father: "O my father! why do you worship that which hears not, sees not and cannot avail you in anything?

(32) [Musa (Moses)] said: "And what is the matter with you. O Samiri? (i.e. why did you do so?)"

(33) He will say: "O my Lord! why have you raised me up blind, while I had sight (before)."

(34) They say: "why does he not bring us a sign (proof) from his Lord?" Has there not come to them the proof of that which is (written) in the former papers [Scriptures, i.e. the Taurat (Torah), and the Injeel (Gospel), about the coming of the Prophet Muhammad صلى الله عليه وسلم]?

(35) why then, did not the believers, men and women, when you heard it (the slander), think good of their own people and say: "This (charge) is an obvious lie ?"

(36) why did they not produce four witnesses? Since they (the slanderers) have not produced witnesses! Then with Allah they are the liars.

(37) And why did you not, when you heard it, say: "It is not right for us to speak of this. Glory be to You (O Allah)! This is a great lie."

(38) And they say: "why does this Messenger (Muhammad صلى الله عليه وسلم) eat food, and walk about in the markets (as we). why is not an angel sent down to him to be a warner with him?

(39) "Or (why) has not a treasure been granted to him, or why has he not a garden whereof he may eat?" And the Zalimun (polytheists and wrong-doers) say: "You follow none but a man bewitched."

(40) And those who expect not a Meeting with Us (i.e. those who deny the Day of Resurrection and the life of the Hereafter) said: "why are not the angels sent down to us, or why do we not see our Lord?" Indeed they think too highly of themselves, and are scornful with great pride.