Prep T1-Q124,Q145

[eploy]

124. 12632-!-item-!-187;#058&008905
Of the 12 temporary employees in a certain company, 4 will be hired as permanent employees. If 5 of the 12 temporary employees are women, how many of the possible groups of 4 temporary employees consist of 3 women and 1 man?

(A) 22
(B) 35
(C) 56
(D) 70
(E) 105

145. 15048-!-item-!-187;#058&010243
Each of 10 machines works at the same constant rate doing a certain job. The amount of time needed by the 10 machines, working together, to complete the job is 16 hours. How many hours would be needed if only 8 of the machines, working together, were used to complete the job?

(A) 18
(B) 20
(C) 22
(D) 24
(E) 26
怎麼算阿
謝謝!!

[hey]

第124題
女生:5人
男生:7人
(5!/3!2!)*(7!/1!6!)=70
選項(D)

第145題
10*16/8=20
選項(B)