# Permutations - Homework Help!

• Nov 17th 2008, 03:59 PM
cnmath16
Permutations - Homework Help!
Hi there,

Just seeing if someone can help me with the answers to some of these questions. I am learning this course on my own, so it is sometimes difficult to come up with the answers.

17. Cecile tosses 5 coins, one after the other.
a) How many different out comes are possible? I said 5! Which is equal to 120 different ways
b) Draw a tree diagram to illustrate the different possibilities? Any ideas as to what the easiest way to go about doing this would be?

c) In how many ways will the first coin turn up heads and the last coin turn up tails?
d) In how many ways will the second, third, and forth coins all turn up heads?
e) Would the same possibilities arise in parts a), b), c), and d) if one coin was tossed 5 times in succession?

All of these questions are worth one mark each. The unit is about Permutations and Combinations in the Grade 12 Data Management course.

Any feedback would be appreciated. Thanks in advance
• Nov 17th 2008, 04:58 PM
Plato
17. Cecile tosses 5 coins, one after the other.
a) How many different out comes are possible? I said 5! Which is equal to 120 different ways
b) Draw
Quote:

Originally Posted by cnmath16
a tree diagram to illustrate the different possibilities? Any ideas as to what the easiest way to go about doing this would be?
c) In how many ways will the first coin turn up heads and the last coin turn up tails?
d) In how many ways will the second, third, and forth coins all turn up heads?
e) Would the same possibilities arise in parts a), b), c), and d) if one coin was tossed 5 times in succession?

The answerer for part(a) is $2^5 = 32$.
The answerer for part(c) is $2^3 = ?$ WHY?.
The answerer for part(d) is $2^2 =?$. Why?
• Nov 21st 2008, 08:55 AM
cnmath16
Thanks for the reply.. but based on the information from the lesson, it doesn't look like they are using exponents in order to solve the question. They are using factorials..
• Nov 21st 2008, 06:38 PM
cnmath16
Quote:

Originally Posted by Plato
17. Cecile tosses 5 coins, one after the other.
a) How many different out comes are possible? I said 5! Which is equal to 120 different ways
b) Draw
The answerer for part(a) is $2^5 = 32$.
The answerer for part(c) is $2^3 = ?$ WHY?.
The answerer for part(d) is $2^2 =?$. Why?

ok.. ignore my previous msg.. after i drew out the tree diagram, it made things a lot more clearer to see....thank you for your help! The last question is... Would the same possibilities arise in parts a), b), c), and d) if one coin was tossed 5 times in succession? I said yes... ?
• Nov 21st 2008, 06:51 PM
Plato
Quote:

Originally Posted by cnmath16
Would the same possibilities arise in parts a), b), c), and d) if one coin was tossed 5 times in succession? I said yes... ?

And you are correct.
• Dec 3rd 2008, 08:37 AM
Carrick
Looks like I'm doing the same question as his part b) and need help with the tree diagram.

Since it was flipping 5 separate coins, i did my tree diagram like;

1st flip < H T

2nd flip < H T

3rd flip < H T

4th flip < H T

5th flip < H T

is this right?

Thanks