Question #b4da1

2 Answers
May 8, 2017

54627300

Explanation:

This is a combination question. We can simply use the formula of nCr.
n=30,r=11.
30C11=54627300
Quite evidently here it is not practical at all to make 54627300 different CD's. Especially of country music.

May 9, 2017

See explanation.

Explanation:

The answer depends on a fact whether the order of the songs is important or not.

If the order does not matter (i.e we treat a CD with songs AB and BA as only one possibility) then there are :

C1130=30!11!19!=2021222324252627282930234557891011

C1130=163,881,900

However if the order of the songs is important (i.e. we treat AB and BA as 2 different pairs) then the number of possibilities rises to:

V1130=30!19!=2021222324252627282930

It is approximately:

V1130=2.1805×1015

Neither variant is practical. It would require very much space to hold those quantities of CDs.