Hi everyone,

I can’t seem to access my citytech email (or the citytech website), at 9pm on Thursday evening 10/13/16 – so if you’ve sent me questions about the homework, I won’t see them tonight! But I do have access to the OpenLab – if you see this message and have a question, you can go ahead and post it here as a comment, I’ll reply in the same way.

Best,

Prof. Reitz

Hi Professor I’m having trouble with question 7C. I’m given 7 total books consisting of; 4 novels, 2 math books and 1 bio. The math books have to stay together so I get the formula 6!4!2! which doesn’t seem to work. The 6! is the total groups; 4! for the novels and 2! for the math but I still seem to get the wrong answer.

Hi Jeron,

If the 6! is for the total groups, then I think you are thinking of the following groups:

1. (2 math books)

2. first novel

3. second novel

4. third novel

5. fourth novel

6. bio book

If so, then once you arrange these groups, the only choice you have left is how to arrange the math books (since the novels have been broken up into individual books, each in its own group, there is no need to rearrange the novels any more).

Does this help? Let me know if not…

-Prof. Reitz

Yep I got it now. I had the novels as their own group which must of messed up my calculations. Thanks

Sweet!