in how many ways 5 different chocolates be distributed . . .

This topic has expert replies
Legendary Member
Posts: 2276
Joined: Sat Oct 14, 2017 6:10 am
Followed by:3 members
in how many ways 5 different chocolates be distributed to 4 children such that any child can get any number of chocolates?

1) 20
2) 24
3) 120
4) 625
5) 1024

The OA is the option E.

How can I get the correct answer here? Can any expert help me? I don't know how to solve this PS question.

GMAT/MBA Expert

User avatar
Legendary Member
Posts: 503
Joined: Thu Jul 20, 2017 9:03 am
Thanked: 86 times
Followed by:15 members
GMAT Score:770

by ErikaPrepScholar » Thu Jan 18, 2018 7:20 am
We must distribute 5 chocolates among 4 children. We know that any child can get any number of chocolates. This means that 3 children could get 1 chocolate and 1 child could get 2 chocolates; or 1 child could get all 5 chocolates and 3 children could get 0 chocolates; or 1 children could get 3 chocolates, 2 children could get 1 chocolate, and 1 child could get 0 chocolates; etc. etc.

This is pretty complex, but we can actually think about it in a pretty simple way. Since which child gets which chocolate next doesn't depend at all on which children already have chocolates, we can think of the distribution of each piece of chocolate independently.

The first chocolate can go to any of the 4 children. That's 4 options.

For each of those options, the second chocolate can go to any of the 4 children. That's another 4 options. This means that there are 4*4=16 options for how the first two chocolates can be given away.

For each of those options, the third chocolate can go to any of the 4 children. That's another 4 options. This means that there are 4*4*4=64 options for how the first three chocolates can be given away.

For each of those options, the fourth chocolate can go to any of the 4 children. That's another 4 options. This means that there are 4*4*4*4=256 options for how the first four chocolates can be given away.

For each of those options, the fifth chocolate can go to any of the 4 children. That's another 4 options. This means that there are 4*4*4*4*4=1024 options for how all four chocolates can be given away. This gives us the correct answer, E.
Image

Erika John - Content Manager/Lead Instructor
https://gmat.prepscholar.com/gmat/s/

Get tutoring from me or another PrepScholar GMAT expert: https://gmat.prepscholar.com/gmat/s/tutoring/

Learn about our exclusive savings for BTG members (up to 25% off) and our 5 day free trial

Check out our PrepScholar GMAT YouTube channel, and read our expert guides on the PrepScholar GMAT blog

User avatar
GMAT Instructor
Posts: 555
Joined: Wed Oct 04, 2017 4:18 pm
Thanked: 180 times
Followed by:12 members

by EconomistGMATTutor » Thu Jan 18, 2018 7:22 am
Hello Vjesus12.

Let's take a look at your question.

Let the 5 cholcolates be : C1 , C2 , C3 , C4 and C5.

And there be 4 Students : S1 , S2, S3 and S4.

Now, The first Chocolate can be given in 4 ways (Either to S1 or S2 or S3 or S4).

The Second Chocolate can be given in 4 ways (Either to S1 or S2 or S3 or S4).

The Third Chocolate can be given in 4 ways (Either to S1 or S2 or S3 or S4).

The Fourth Chocolate can be given in 4 ways (Either to S1 or S2 or S3 or S4).

The Fifth Chocolate can be given in 4 ways (Either to S1 or S2 or S3 or S4).

So, we have $$4\cdot4\cdot4\cdot4\cdot4=4^5=1,024\ possible\ ways.$$ This is why the correct answer is the option E .

I hope this answer can help you.

I'm available if you'd like a follow-up.

Regards.
GMAT Prep From The Economist
We offer 70+ point score improvement money back guarantee.
Our average student improves 98 points.

Image