Answer:
<em>Choose the first alternative</em>
![\displaystyle P=\frac{_{1}^{6}\textrm{C}\ _{1}^{5}\textrm{C}}{_{2}^{20}\textrm{C}}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20P%3D%5Cfrac%7B_%7B1%7D%5E%7B6%7D%5Ctextrm%7BC%7D%5C%20_%7B1%7D%5E%7B5%7D%5Ctextrm%7BC%7D%7D%7B_%7B2%7D%5E%7B20%7D%5Ctextrm%7BC%7D%7D)
Step-by-step explanation:
<u>Probabilities</u>
The requested probability can be computed as the ratio between the number of ways to choose two sophomores in alternate positions
and the total number of possible choices
, i.e.
![\displaystyle P=\frac{N_s}{N_t}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20P%3D%5Cfrac%7BN_s%7D%7BN_t%7D)
There are 6 sophomores and 14 freshmen to choose from each separate set. There are 20 students in total
We'll assume the positions of the selections are NOT significative, i.e. student A/student B is the same as student B/student A.
To choose 2 sophomores out of the 6 available, the first position has 6 elements to choose from, the second has now only 5
![_{1}^{6}\textrm{C}\ _{1}^{5}\textrm{C} \text{ ways to do it}](https://tex.z-dn.net/?f=_%7B1%7D%5E%7B6%7D%5Ctextrm%7BC%7D%5C%20_%7B1%7D%5E%7B5%7D%5Ctextrm%7BC%7D%20%5Ctext%7B%20ways%20to%20do%20it%7D)
The total number of possible choices is
![_{2}^{20}\textrm{C} \text{ ways to do it}](https://tex.z-dn.net/?f=_%7B2%7D%5E%7B20%7D%5Ctextrm%7BC%7D%20%5Ctext%7B%20ways%20to%20do%20it%7D)
The probability is then
![\boxed{\displaystyle P=\frac{_{1}^{6}\textrm{C}\ _{1}^{5}\textrm{C}}{_{2}^{20}\textrm{C}}}](https://tex.z-dn.net/?f=%5Cboxed%7B%5Cdisplaystyle%20P%3D%5Cfrac%7B_%7B1%7D%5E%7B6%7D%5Ctextrm%7BC%7D%5C%20_%7B1%7D%5E%7B5%7D%5Ctextrm%7BC%7D%7D%7B_%7B2%7D%5E%7B20%7D%5Ctextrm%7BC%7D%7D%7D)
Choose the first alternative
Answer:
144 it is D
Step-by-step explanation:
A straight line is 180°. 180°-135°=55°, so x=55°, which is an acute angle because it is less than 90°.
Answer:
he will have saved 45$
Step-by-step explanation:
if you take 2 from every 5 and 5 x 15 = 150, you would do 2 x 15 and get 30. So, the answer is 30$