Always this one type of perm/comb question that screws me over every time (1 Viewer)

[hsc3hard5me]

Can someone explain how this works, this is one of the only common types that always gets me

 

[faisalabdul16]

Do you have the answers?

 

[hsc3hard5me]

Do you have the answers?

a is 8!/(5!3!)

b is 1/28

 

[QZP]

^ nope. Where did you get that answer from? Unless im doing something major wrong

 

[hsc3hard5me]

^ nope

what do you mean nope :\

 

[enigma_1]

a is 8!/(5!3!)

b is 1/28

as if, that can't be right

what t/b or resource is this?

 

[seventhroot]

as if, that can't be right

what t/b or resource is this?

inb4MIF

 

[QZP]

i) Choose 3 people to sit on the 3-seat-table. Then arrange both groups accordingly. 8C3 x 2! x 4!
ii) 1 - P(couple sit together) = 1 - [ P(both on 3-seat-table) + P(both on 5-seat-table)]
= 1 - [ (6 x 2! x 4!) + (6C3 x 4! x 2!) ] /(result from i)

 

[enigma_1]

inb4MIF

hahahha I had a feeling someone'd say this

The font's different though :/ I've never seen a textbook with that particular font.

 

[hsc3hard5me]

MIF? Close boys, Sydney boys trial paper lel.

 

[faisalabdul16]

MIF? Close boys, Sydney boys trial paper lel.

What year?

 

[hsc3hard5me]

i) Choose 3 people to sit on the 3-seat-table. Then arrange both groups accordingly. 8C3 x 2! x 4!
ii) 1 - P(couple sit together) = 1 - [ P(both on 3-seat-table) + P(both on 5-seat-table)]
= 1 - [ (6 x 2! x 4!) + (6C3 x 4! x 2!) ] /(result from i)

Correct me if I'm wrong but these table questions take into account position, so you cant use combination?

 

[hsc3hard5me]

What year?

2000

 

[photastic]

The dot questions are harder.

 

[braintic]

Correct me if I'm wrong but these table questions take into account position, so you cant use combination?

Part (ii) is a 2 Unit question. It doesn't need any perms and combs.
It is just (3/8)*(5/7) + (5/8)*(3/7)

 

[QZP]

Part (ii) is a 2 Unit question. It doesn't need any perms and combs.
It is just (3/8)*(5/7) + (5/8)*(3/7)

Can you explain o;

Edit: nvm figured it out. nice

 

[braintic]

Can you explain o;

3 chances in 8 of the male being placed at the table of 3 AND THEN 5 chances in 7 of the female being placed at the table of 5

OR

the other way round