 <translate> Student: A card shop contains 10 birthday cards, 10 holiday cards, and 9 graduation cards. If three cards are purchased at random from the shop, what is the probability that the three cards will be of the same type?
Options:
(A) 3/29
(B) 12/58
(C) 12/840
(D) 7/841
(E) 12/841.
Another student: Let's say, hmmm...
 <yor> Akẹ́kọ̀ọ́: Ilé ìtajà tí wọ́n ti ń ta káàdì ìbíni kan ní káàdì ìbíni mẹ́wàá, káàdì ìsinmi mẹ́wàá àti káàdì ìkẹ́kọ̀ọ́yege mẹ́sàn-án. Bí wọ́n bá ra káàdì mẹ́ta lọ́tùn-ún lósì ní ṣọ́ọ̀bù, kí ló ṣeé ṣe kó jẹ́ pé irú káàdì kan náà ni wọ́n? Àwọn àyè: (A) 3/29 (B) 12/58 (C) 12/840 ì ì (D) 7/841 (E) 12/841. Ọmọ iléèwé mìíràn: Ẹ jẹ́ ká sọ pé, hmmm... 