Question

The digits 5, 3, 6, 2 and 7 are used to make a 5-digit number. How many different numbers are possible if the digits 3, 2 and 7 must be together?

Answer 1

36 is the answer

Answer 2

You may choose 3 digits out of 5, and you may place them in different orders. Right?

Answer 3

So, it is \(_5P^3\)

Answer 4

Do you know how to calculate permutations?

Answer 5

5P3=60 and that's not the answer.

Answer 6

Is 36 the answer, plz tel me

Answer 7

36 is indeed correct, stated by @nishika17

Answer 8

Oh! It's something else. Never mind.

Answer 9

I read the question differently—my apologies.

Answer 10

I also calculated it correctly but want to know why the 5-digit part has no affect?

Answer 11

3! x 3!=36

Answer 12

Right there.

Answer 13

The number of ways three digits can stay together is 3!.

Answer 14

is it 5! * 3! = 720 ??

Answer 15

ok, I understand @ParthKohli, thanks.

Answer 16

You're welcome!

Answer 17

@ganpat that is not correct.

Answer 18

oh sorry, i meant 3! * 3! = 36.. :(

Answer 19

hey, can you help me out with this @ParthKohli
Maria, Steven, James, Sofia, Nin and Alfredo are standing next to each other. Calculate how many ways this can be done if Maria and James are not to stand next to each other.

Answer 20

Hint: Probability of them not standing next to each other = 1 - P(Standing each other).

Answer 21

yep but I don't know how to find the standing next to each other part.

Answer 22

There are 5 ways for them to stand with each other.

M J _ _ _ _
_ M J _ _ _
_ _ M J _ _
_ _ _ M J _
_ _ _ _ M J

Answer 23

Well, the number of ways they don't stand together is the number of ways all could stand - the number of ways they stand together.

Answer 24

is there another way to figure it out besides listing it?

Answer 25

the 5 ways for them to stand with each other*

Answer 26

I find the 'listing' way visual—and that is how I learnt it.

Answer 27

okok.

Answer 28

The number of ways the 6 people may stand = 6! = 720
Now subtract 5 from 720, and you get 715.

Answer 29

Is that the right answer?

Answer 30

Wait.. I am confused whether to divide of subtract.

Answer 31

nope it's 6!-2!x5!=480

Answer 32

or*

Answer 33

Oh. I am confused myself now :/

Answer 34

Let me just review the concept. Sorry for the inconvenience.

Answer 35

it's ok.

Answer 36

Well.

5 ways to place them, but when we do, we have 4 blanks left. The ways you could fill those 4 spots is 4! = 24.

Then, we multiply the number of ways to place M and J, and get 24 * 5 = 120.

Answer 37

Hmm... you should look at the 3rd here - http://answers.yahoo.com/question/index?qid=20100206071826AAPHkCK

Answer 38

I am confused on the second question that you asked :/