A community for students.
Here's the question you clicked on:
 0 viewing
mathmath333
 one year ago
counting question
mathmath333
 one year ago
counting question

This Question is Closed

mathmath333
 one year ago
Best ResponseYou've already chosen the best response.0dw:1440892159292:dw

mathmath333
 one year ago
Best ResponseYou've already chosen the best response.0In how many different ways can we put all 5 identical balls in a 3\(\times\)3 grid . Such that each row contains was atleast one ball.

mathmath333
 one year ago
Best ResponseYou've already chosen the best response.0@Nnesha please remove question mark

Nnesha
 one year ago
Best ResponseYou've already chosen the best response.0no mod power today sorry ;~;

IrishBoy123
 one year ago
Best ResponseYou've already chosen the best response.2think about choosing 4 blanks squares from 9, maybe

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3There are 9 C 5 = 126 ways to place the balls without worrying about whether all rows have at least one ball or not. If we focus on the cases where one row is left out, like row 3 left out, then we have 6 C 5 = 6 ways to fill up the first two rows only. So there are 3*6 = 18 ways to fill up 2 rows only leaving out one row blank The last thing to do is subtract 126  18 = 108

mathmath333
 one year ago
Best ResponseYou've already chosen the best response.0how is leaving one row empty and chossing 5 out 6 and multiplying by 3 is similar to condition at least one row has one ball

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3Well you only have 2 options: you either have each row have at least 1 ball OR one row gets left out entirely when I calculated the "18", that's the number of ways to leave out 1 row I subtracted from 126 because of this property (number of ways where each row gets at least 1 ball) + (number of ways to leave out one row entirely) = total number of ways to fill up the slots
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.