Answer:
1-D)40
2-D ![\frac{2}{5}](https://tex.z-dn.net/?f=%5Cfrac%7B2%7D%7B5%7D)
3-B) ![\frac{1}{4}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B4%7D)
4 There are 120 permutations.
5 There are 165 combinations.
6 Sample space is {HH,HT,TH,TT}
Step-by-step explanation:
Number 1
Step 1
The fundamental counting theorem states that for process that can be carried out in k steps where the fist step can be done in
ways, step 2 can be done in
number of ways and the
can be done in
number of ways, the number of ways to complete this task is
ways.
Step 2
We now realize that this process can be carried out in 2 steps , there are 8 ways to complete the first step and 5 ways to complete the second step. The number of ways to carry out this calculation is shown below,
The correct answer is D.
Number 2
Step 1
in this step we calculate the number total number of cans in the ice chest. Since there are 30 red cans and 20 green cans, there is a total of 50 cans.
Step 2
In this step we find the probability of grabbing a green can by dividing the total number of green cans by the total number of cans. The calculation for the probability is shown below,
![P(G)=\frac{20}{50} =\frac{2}{5}.](https://tex.z-dn.net/?f=P%28G%29%3D%5Cfrac%7B20%7D%7B50%7D%20%3D%5Cfrac%7B2%7D%7B5%7D.)
The correct answer is D.
Number 3
Step 1
The first step is to realize that there is a
chance of getting a head when flipping a coin. When a die is rolled the sample space is {1,2,3,4,5,6}. From this we can tell that there are 3 out of 6 ways to get an even number from this sample space. The probability for an even number is ![\frac{3}{6}](https://tex.z-dn.net/?f=%5Cfrac%7B3%7D%7B6%7D)
Step 2
The second step in this process is to realize that these two events are independent hence we multiply the individual probabilities of the different outcomes to get the odds of a head and an even number. This calculation is shown below,
![P(H\&E)=\frac{1}{2}\times \frac{3}{6}=\frac{3}{12}=\frac{1}{4}.](https://tex.z-dn.net/?f=P%28H%5C%26E%29%3D%5Cfrac%7B1%7D%7B2%7D%5Ctimes%20%5Cfrac%7B3%7D%7B6%7D%3D%5Cfrac%7B3%7D%7B12%7D%3D%5Cfrac%7B1%7D%7B4%7D.)
The correct answer is D
Number 4
Step 1
The first step is to realize that the only unique letters in INNOVATIVE are {I,N,O,V,A,T,E}, i.e there are only seven unique permutations of these letters.
Step 2
The second step is to calculate the number of 4 permutations of 7 objects.
This is calculated as shown below,
![P(7,4)=\frac{7!}{4!} =\frac{7\times6\times5\times 4!}{4!} =210.](https://tex.z-dn.net/?f=P%287%2C4%29%3D%5Cfrac%7B7%21%7D%7B4%21%7D%20%3D%5Cfrac%7B7%5Ctimes6%5Ctimes5%5Ctimes%204%21%7D%7B4%21%7D%20%3D210.)
There are 210 unique permutations of these letters.
Number 5
Step 1
Realize that the number of r combinations of n objects is ,![C(n,r)=^nC_r=\frac{n!}{r!(n-r)!}.](https://tex.z-dn.net/?f=C%28n%2Cr%29%3D%5EnC_r%3D%5Cfrac%7Bn%21%7D%7Br%21%28n-r%29%21%7D.)
Step 2
We realize that in this problem we have to make 3 combinations of 11 objects. The calculation to determine the number of combination sis shown below,
![C(11,3)=^{11}C_3=\frac{11!}{3!\cdot(11-3)!} =\frac{11\times 10\times9\times8!}{3!\times 8!}=165](https://tex.z-dn.net/?f=C%2811%2C3%29%3D%5E%7B11%7DC_3%3D%5Cfrac%7B11%21%7D%7B3%21%5Ccdot%2811-3%29%21%7D%20%3D%5Cfrac%7B11%5Ctimes%2010%5Ctimes9%5Ctimes8%21%7D%7B3%21%5Ctimes%208%21%7D%3D165)
Number 6
Step 1
We list the outcomes where we first get a head. These outcomes are {HH,HT}. Next we list the outcomes in which we get a tail first. These outcomes are {TH,TT }
Step 2
In this step we combine all the outcomes step 1. The combined list of outcomes is {HH,HT, TH, TT}