A supervisor is evaluating 10 subordinates for their annual performance reviews. According to a new corporate policy, for every 10 employees, 2 must be evaluated ad “exceeds expectations”. 7 as “meets expectations”, and 1 as “does not meet expectations”. How many different ways is it possible for the supervisor to assign these ratings? A) 360 B) 5040 C) 10,080 D) 3,628.800. I know we need to use permutation however, I am not able to get the correct answer unless I divide the permuation with some no. Please explain?
10!/[(7!)(2)(1)] = 360 A)
Got it thanks… I was just not thinking rite…
sharp you are on FIRE!! can you explain the reasoning behind, i was think its 10!/ (something)
i don’t remember what reading it’s from but basically if you have n objects and you want to split them into groups of size a,b,c it can be done in n!/[(a!)(b!)(c!)] ways
also it’s 3+ groups and order doesn’t matter, so you’ll want to label.
Another way of looking at it is out of 10, select 2 in 10C2 ways. Then out of remaining 8, select 7 in 8C7 ways. Remaining 1 is chosen in 1 way. Total ways: 10C2 * 8C7 = 360
the dumb way: 10P3 = 720 and the result gotta be less, look at the answers, ur left with A only why do only stupid things work in my mind ?