Question

Li has to read four books from a list of 10 books.

How many sets of four books can be made?

Answer 1

You will want to use the probability combination formula to figure out how many sets of books can be read

\[nCr = \frac {n!}{r!(n-r)!}\]
can you pick out, from the information given, what will n= and r=?

Answer 2

n is 10 r is 4?

Answer 3

i figured it out

Answer 4

thanks though

Answer 5

good job ^_^
yep, n=10, r=4

Answer 6

lol