Answer:
1120 combinations of four teachers include exactly one of either Mrs. Vera or Mr. Jan.
Step-by-step explanation:
The order in which the teachers are chosen is not important, which means that the combinations formula is used to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
In this question:
1 from a set of 2(Either Mrs. Vera or Mr. Jan).
3 from a set of 18 - 2 = 16. So
![C_{2,1}C_{16,3} = \frac{2!}{1!1!} \times \frac{16!}{3!13!} = 1120](https://tex.z-dn.net/?f=C_%7B2%2C1%7DC_%7B16%2C3%7D%20%3D%20%5Cfrac%7B2%21%7D%7B1%211%21%7D%20%5Ctimes%20%5Cfrac%7B16%21%7D%7B3%2113%21%7D%20%3D%201120)
1120 combinations of four teachers include exactly one of either Mrs. Vera or Mr. Jan.
Answer:
12/19?
11/19?
Step-by-step explanation:
Answer:
C
Step-by-step explanation:
Distribute the negative, (2x^2 + 5) + (-4x+3)
Add like terms, 2x^2 - 4x +(5+3)
2x^2-4x+8
Answer:
X=155 -that's the answer good luck!
Speed =wavelength x frequency
= 2x1.5 = 3m/s