# math destroyer question

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#### csulapredental

##### Full Member

how many diff ways can 2 girls and 3 boys sit in a row if the 2 girls always sit side by side.
I'm trying to apply chads method but i can't tell how. clearly order matters and when order matters he just puts the number of selections on top and thats it because order matters... so it should be 5! but its not..

another one is how many ways can the same 4 physics books, 3 algebra books, and 2 chem books be arranged on a self.. again order matters so it should be 9! ??

i feel like his way isn't applying.
even if i use the equation of n!/(n-r)! there isn't a clear r to plug in!???

pelase help

#### ry_guy_chi

##### Full Member
Its been a while since I did these, but I think this is number 1. And the second one is done the same way. FYI, order matters here and there is no replacement (obviously), so you don't divide by anything.

Oh sorry, I thought it was 3 girls and 2 boys lol. It's late… and since the girls must always sit side by side…ya, didn't see that part either lol. Look at the second attachment.

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#### csulapredental

##### Full Member
Its been a while since I did these, but I think this is number 1. And the second one is done the same way. FYI, order matters here and there is no replacement (obviously), so you don't divide by anything.

Oh sorry, I thought it was 3 girls and 2 boys lol. It's late… and since the girls must always sit side by side…ya, didn't see that part either lol. Look at the second attachment.

#### johndoe777

##### Membership Revoked
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2+ Year Member
wtf, are you seriously asking this question. this problem come directly from math destroyer. i know because i did this problem from math destroyer. go look at the answer on the back of the damn book and read the explanation. nobody going to walk you step by step with every damn problems.

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#### csulapredental

##### Full Member
wtf, are you seriously asking this question. this problem come directly from math destroyer because i know i did this problem from math destroyer. go look at the answer on the back of the damn book and read the explanation. nobody going to walk you step by step with every damn problems.
stop crying
the question refers to using CHADS METHOD SPECIFICALLY
obviously the answer is in the back but it was asked on here for a reason gtfo

#### johndoe777

##### Membership Revoked
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2+ Year Member
you stupid as hell, you ask every damn questions on here expecting people to hold your hands on every little thing. why don't you gtfo here and actually study the damn material yourself.

#### csulapredental

##### Full Member
you stupid as hell, you ask every damn questions on here expecting people to hold you hands on every little thing. why don't you gtfo here and actually study the damn material yourself.
why r u still speaking

#### johndoe777

##### Membership Revoked
Removed
2+ Year Member
why are you still dumb?

#### roy williams II

##### Full Member
2+ Year Member
Don't worry, I'm struggling with this too! Permutations and combinations are no fun.