Question

a lock has a code of 5 numbers between 1 and 20 . If no numbers in the code are allowed to repeat, how many different codes could be made?

so it is not 20C5

so can you tell me exactly what the answer is?
I can try to figure out the other 9 questions from this..please
blended learning is bad
my parent don´t know either

thanks

Answer 1

20C5 would be the answer if the order in the codes doesn't matter, but
surely the order does matter, so it must be
20P5
or 20*19*18*17*16 = 1860480

Answer 2

THANK YOU!!!!LOVE U~~