The word(s) "three" appears 22 time(s) in 21 verse(s) in Quran in Abdullah Yusuf Ali translation.

(11) (Some) say they were three, the dog being the fourth among them; (others) say they were five, the dog being the sixth,- doubtfully guessing at the unknown; (yet others) say they were seven, the dog being the eighth. Say thou: "My Lord knoweth best their number; It is but few that know their (real case)." Enter not, therefore, into controversies concerning them, except on a matter that is clear, nor consult any of them about (the affair of) the Sleepers.

(12) So they stayed in their Cave three hundred years, and (some) add nine (more)

(13) (Zakariya) said: "O my Lord! give me a Sign." "Thy Sign," was the answer, "Shall be that thou shalt speak to no man for three nights, although thou art not dumb."

(14) So We listened to him: and We granted him Yahya: We cured his wife's (Barrenness) for him. These (three) were ever quick in emulation in good works; they used to call on Us with love and reverence, and humble themselves before Us.

(15) O ye who believe! let those whom your right hands possess, and the (children) among you who have not come of age ask your permission (before they come to your presence), on three occasions: before morning prayer; the while ye doff your clothes for the noonday heat; and after the late-night prayer: these are your three times of undress: outside those times it is not wrong for you or for them to move about attending to each other: Thus does Allah make clear the Signs to you: for Allah is full of knowledge and wisdom.

(16) Praise be to Allah, Who created (out of nothing) the heavens and the earth, Who made the angels, messengers with wings,- two, or three, or four (pairs): He adds to Creation as He pleases: for Allah has power over all things.

(17) He created you (all) from a single person: then created, of like nature, his mate; and he sent down for you eight head of cattle in pairs: He makes you, in the wombs of your mothers, in stages, one after another, in three veils of darkness. such is Allah, your Lord and Cherisher: to Him belongs (all) dominion. There is no god but He: then how are ye turned away (from your true Centre)?

(18) And ye shall be sorted out into three classes.

(19) Seest thou not that Allah doth know (all) that is in the heavens and on earth? There is not a secret consultation between three, but He makes the fourth among them, - Nor between five but He makes the sixth,- nor between fewer nor more, but He is in their midst, wheresoever they be: In the end will He tell them the truth of their conduct, on the Day of Judgment. For Allah has full knowledge of all things.

(20) Such of your women as have passed the age of monthly courses, for them the prescribed period, if ye have any doubts, is three months, and for those who have no courses (it is the same): for those who carry (life within their wombs), their period is until they deliver their burdens: and for those who fear Allah, He will make their path easy.