Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:
There are 9 books on a shelf, 7 hard cover and 2 soft cover. [#permalink]
02 Oct 2003, 07:48
0% (00:00) correct
0% (00:00) wrong based on 0 sessions
There are 9 books on a shelf, 7 hard cover and 2 soft cover. How many different combinations exist in which you choose 4 books from the 9 and have at least one of them be a soft cover book? _________________
why don't u try the permutation/combinations stuff on this website.
U can also consult any basic book on combinations/permutations or search on google for some stuff. I guess someone posted in share GMAT expe. section a link to some basic permutation/combo site. Check it out
Remember, u would want to be thorough in this area cause more and more questions based on them have begun to appear on GMAT
also 9! = 1*2*3...*8*9
it's pretty late here... time to sleep...
nowadays even in sleep i get these tormenting SC's...