DrGreg said:
I don't think you have counted "choosing none". In my (much easier) method in post #12, I got 44 = 256. (64 is 43.)
Yes, I counted "choosing none," but I only counted 3 of the "special" condiments, and even then, I forgot to count the 63 possibilities of hamburgers having some combination of those 3 "special" condiments only (not using any of the other 11). Therefore, the total should have been 131,135.
The correct count should have been as follows:
For the 4 "special" condiments, we have:
a1 = a "normal" amount of condiment "a"
a2 = a "light" amount of condiment "a"
a3 = a "heavy" amount of condiment "a"
Also, we have b1, b2, b3, c1, c2, c3, d1, d2, and d3
There is the case that we choose none of the special condiments (1 case)
We can choose anyone of the special condiments (12 cases) ---- _4C_1 \times _3C_1[/tex]<br />
We can choose any 2: 54 cases ---- _4C_2 \times _3C_1 \times _3C_1[/tex]<br />
Choose any 3: 108 cases ---- _4C_3 \times _3C_1 \times _3C_1 \times _3C_1[/tex]&lt;br /&gt;
Choose any 4: 81 cases ---- _4C_4 \times _3C_1 \times _3C_1 \times _3C_1 \times _3C_1[/tex] &amp;lt;br /&amp;gt;
(don&amp;amp;#039;t forget, that you can&amp;amp;#039;t choose combinations like: a1a2, a1b1b2, a1a2a3b2, etc.)&amp;lt;br /&amp;gt;
&amp;lt;br /&amp;gt;
Total possible combinations of the special condiments: 1 +12 + 54 + 108 + 81 = 256&amp;lt;br /&amp;gt;
Although this is the same number that DrGreg came up with, 4^4[/tex] has no meaning in this problem since we have 4 items with 3 states each.&amp;amp;lt;br /&amp;amp;gt;
&amp;amp;lt;br /&amp;amp;gt;
So then we have 1 combination of no condiments, 2047 combinations of the 11 main condiments and 255 combinations of the 4 special condiments. Plus, we have 2047 x 255 = 521,985 ways to use some of the 11 main condiments, along with some of the 4 special ones&amp;amp;lt;br /&amp;amp;gt;
&amp;amp;lt;br /&amp;amp;gt;
The grand total of combinations of condiments is therefore 1 + 2047 + 255 + 521,985 = 524,288