Answer:
0 maybe?
Step-by-step explanation:
49/12
Just mulitply the top and the bottom across.
7*7/4*3
49/12
9880 different possibilities are there in Sally's new combination option second 9880 is correct.
<h3>What is permutation and combination?</h3>
A permutation is the number of different ways a set can be organized; order matters in permutations, but not in combinations.
We have:
Total unique numbers consists in a Sally locker = 3
From the digits 0 to 39
Total numbers = 40
Apply combination formula:
= C(40, 3)
= 40!/(3!37!)
= 9880
Thus, 9880 different possibilities are there in Sally's new combination option second 9880 is correct.
Learn more about permutation and combination here:
brainly.com/question/2295036
#SPJ1
Answer:
The magnetic field is
Direction is inward
Step-by-step explanation:
The diagram for this question is shown on the first uploaded image
From the question we are told that
The radius of BC is 
The radius of DA is 
The length of CD is 
The length of AB is 
The current is 
The magnetic field is mathematically represented as

![B = \frac{\mu_o I}{4 \pi } [ \frac{\theta_{DA}}{r_{DA}} + \frac{\theta_{BC}}{r_{BC}}+ \frac{\theta_{CD}}{r_{CD}}+\frac{\theta_{AB}}{r_{AB}}]](https://tex.z-dn.net/?f=B%20%3D%20%20%5Cfrac%7B%5Cmu_o%20I%7D%7B4%20%5Cpi%20%7D%20%5B%20%5Cfrac%7B%5Ctheta_%7BDA%7D%7D%7Br_%7BDA%7D%7D%20%2B%20%5Cfrac%7B%5Ctheta_%7BBC%7D%7D%7Br_%7BBC%7D%7D%2B%20%5Cfrac%7B%5Ctheta_%7BCD%7D%7D%7Br_%7BCD%7D%7D%2B%5Cfrac%7B%5Ctheta_%7BAB%7D%7D%7Br_%7BAB%7D%7D%5D)
Where

Where 

so
![B = \frac{\mu_o I}{4 \pi } [ \frac{\frac{2\pi}{3} }{0.20} - \frac{\frac{2\pi}{3}}{0.30}}+ \frac{0}{0.10}+\frac{0}{0.10}]](https://tex.z-dn.net/?f=B%20%3D%20%20%5Cfrac%7B%5Cmu_o%20I%7D%7B4%20%5Cpi%20%7D%20%5B%20%5Cfrac%7B%5Cfrac%7B2%5Cpi%7D%7B3%7D%20%7D%7B0.20%7D%20-%20%5Cfrac%7B%5Cfrac%7B2%5Cpi%7D%7B3%7D%7D%7B0.30%7D%7D%2B%20%5Cfrac%7B0%7D%7B0.10%7D%2B%5Cfrac%7B0%7D%7B0.10%7D%5D)

The direction is into the page
This because the magnitude of the magnetic field due to arc BC whose direction is outward is less than that of DA whose direction is inward
This is because according to Fleming's Left Hand Rule the direction of current is perpendicular to the direction of magnetic field so since current in arc BC and DA are moving in opposite direction their magnetic field will also be moving in opposite direction
I would argue that it does due to that if it increased, it's either from a 30% chance that nothing changed or that the teachers did it. Since 100-30=70, there's a 70 percent chance that the teaching effect did work!