 
 <translate> The question is: Joey is planning to throw a small party and for that he needs to do the following tasks:
I. Decide guest list
II. Send invites
III. Arrange catering
IV. Decide the venue
V. Rent a music system
The tasks can be done in any order as long as the invites are sent after the guest list is decided. In how many ways can Joey do the five tasks listed above?
Options:
(A) 24
(B) 48
(C) 60
(D) 120
(E) 240
Step-by-step reasoning process: These 5 tasks can be arranged in 5! = 120 ways. In half of them invites are sentafterthe guest list is decided and in half of them before. So, there are total of 120/2 = 60 ways to arrange the task so that the invites are sent after the guest list is decided.
 <hau> Tambayar ita ce, Joey yana shirin yin wani karamin biki kuma don haka yana bukatar yin wadannan ayyuka: I. Yanke shawarar jerin baƙi Na biyu. Aika gayyata Na uku. Ka shirya abinci. Ƙwaƙwalwa. Ka yanke shawarar wurin da za a yi taron V. Yi hayar tsarin kiɗa Ana iya yin ayyukan a kowane tsari muddin aka aika da gayyata bayan an yanke shawarar jerin baƙi. A hanyoyi nawa ne Joey zai iya yin ayyuka biyar da aka lissafa a sama? Zaɓuɓɓuka: (A) 24 (B) 48 (C) 60 (D) 120 (E) 240 da kuma Tsarin tunani mataki-mataki: Wadannan ayyuka 5 ana iya shirya su ta hanyoyi 5! = 120. A rabin su ana aikawa da gayyata bayan an yanke shawarar jerin baƙi kuma a rabin su kafin. Don haka, akwai jimillar 120/2 = 60 hanyoyin da za a shirya aikin don a aika da gayyata bayan an yanke shawarar jerin baƙi. 