Question 1108562
<pre>
The trio that must stand together can be arranged in 3! = 6 ways.

Then for each of those 6 ways, we have 4 "things" to arrange.
[The 4 "things" consist of 3 single persons and 1 trio.]

That's 4! - 24 ways.

Answer:  3!&#8729;4! = 6&#8729;24 = 144 

Edwin</pre>