Hey guys I have a question here:
Two drugs are to be tested on 60 lab mice. Each mouse receives either one drug or acts as a control. Drug A is to be tested on 22 of the mice. Drug B is to be tested on another 22 of the mice. The remaining 16 mice are to act as a control group.How many different ways can the tests performed?
the answer provided by my teacher is :
60!/( 22! 22! 16! )
but may i know why?....can someone explain it?
Thanks very much