what question theres none
Answer:
you did not supply enough information
Answer:
Ten added to the difference of six and four. Or, the difference of six and four added to ten.
Step-by-step explanation:
This is a combination problem. Order does not matter and the books are all different. You would write this as 21C5 or
. Combinations are not fractions.
The answer is 
which = 20349 different ways these books can be chosen.