In a cosmetics company , there are 5 engineers out of 20 officers. If 3 officers are picked at random, what is the probability that all are engineers.  Pick
A) 3/114  B) 1/114  C) 1/1140  D) 1/1170  E) None of these
Explanation :   No. of engineer = 5.   No. of total non-engineer = 15.   Total no. of officers = 20 of which 3 officers are picked.   P(all are engineers) =   =&gt; No. of selection with restriction / No. of selection without restriction   =&gt; 5C3 / 20C3 .   =&gt; 10 / 1140.   =&gt; 1 / 114.   Answer : 1/114
<result>B</result>
In a cosmetics company , there are 5 engineers out of 20 officers. If 3 officers are picked at random, what is the probability that all are engineers.