MATH HELP 10POINTS TO BEST

Answer then explain
1.Nick Keep all his CD's om a gym bag the bag has 10 heavy metal CD's, 4 Rock CD's and 9 country CD's .Nick randomly pulls out a heavy metal CD then he pulls out another CD at random. What is the probability that this second CD will be country

2. Maurice and Jillian are rolling two six sided dice. Maurice rolls both dice and obtains the sum of 10. If there are 36 possible outcomes, what is the probability that Jillians total on her next roll will be greater than 10

1. 9/22. It would be this because he has 9 country cd's to pick but then when he picked the last one and never put it back in the total amount of cd's dropped to 22.


2. 2/36 --> 1/18 This would happen because if you list the combinations and add them the only 2 of combinations show as 5 and 6......and 6 and 6

1)
chances of getting a heavy metal cd first time:
10/23
chances of getting rock cd AFTER picking up a heavy metal cd first time:
10/23 * 4/22
= 10/506
= 20/253
~= 0.08

It would help if you draw tree diagrams :)

2)
3/36 to get a sum of 10 first roll
[Combinations of sums of 10: (4,6), (5,5), (6,4)]
chances of getting a result greater than 10 = 3/36
[Combinations of sums greater than 10: (5,6), (6,5), (6,6)]
so probability of getting a sum of 10 first roll AND Pr(x>10) second = 3/36 * 3/36
= 1/144
~=0.00694444

Hope this helped, it's been a year since I've done this stuff :)

1. 9/22 are the odds for pulling a COUNTRY CD second

2. 3/36 as there are only 3 combinations on the dice that equal 11 or greater.
Die 1. Die 2.
Six. Five
Five. Six
Six. six

10 +4+9=23 so 10/23 for heavy metal than 9/22 for country





11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 so 27/37

9 / ((10-1) + 4 + 9)
nine are country out of the remaining 22



for 11: two ways [5+6 or 6+5]
for 12: only one way [6+6]
that's 3/36