Since these are special positions, the order counts, so
what is 15x14x13 ?
In a club 15 members choose from them a president , secretary and a treasurer. How many different states of candidates can be chosen?
3 answers
What is 15!/3!12!?
answer 15*14*13/3*2=5*7*13
answer 15*14*13/3*2=5*7*13
Ok, I agree with Reiny, I wasn't counting them as special positions.