# Probability question / DAT DESTROYER QR

This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.

#### hasanein4u

##### Full Member
10+ Year Member
In questions 86 and 87

I thought that order does not matter but it sounds like it does from the formula they used in the solution

Could you explain how do we know if the order matters or not (especially for these two questions because they made me confused)

Thanks

Members don't see this ad.

#### Djdents

##### Full Member
10+ Year Member
In questions 86 and 87

I thought that order does not matter but it sounds like it does from the formula they used in the solution

Could you explain how do we know if the order matters or not (especially for these two questions because they made me confused)

Thanks

post the quesiton

#### sagarkanodiya

##### Full Member
10+ Year Member
86.
Four rooms are painted and each room has to be different color (order does matter) then you
for room A 9 color possibility, for room B since you already used 1 out of 9 color in room A now you have 8 choice for Room B, form room C you have 7 choices , and for room D you have 6 choices.
9*8*7*6=3,024

87. Four different positions and total 6 persons to chose from.
Order does matter since One person can not hold two positions,

6*5*4*3=360

I strongly recommend you to watch Chad's video on Probability, gives you totally different view on this topic.

#### hasanein4u

##### Full Member
10+ Year Member
86.
Four rooms are painted and each room has to be different color (order does matter) then you
for room A 9 color possibility, for room B since you already used 1 out of 9 color in room A now you have 8 choice for Room B, form room C you have 7 choices , and for room D you have 6 choices.
9*8*7*6=3,024

87. Four different positions and total 6 persons to chose from.
Order does matter since One person can not hold two positions,

6*5*4*3=360

I strongly recommend you to watch Chad's video on Probability, gives you totally different view on this topic.

I do not have chad for math

but you said the thing I needed to make sure about... when it says that that options are distinct that means (order does matter)

Last edited:

#### sagarkanodiya

##### Full Member
10+ Year Member
when asked for different or distinct, order does matter and it's a permutation problem
when order does not matter, it is combination .