Answer:
11/20
Step-by-step explanation:
At the beginning, the number of marbles in the box are:
10 green marbles
11 white marbles
The first marble chosen is green, and then it is not replaced in the box. Therefore, the number of green marbles left in the box is 9.
Therefore, the total number of marbles left in the box is:
Now we want to find the probability to choose a white marble. The number of white marble is
Therefore, the probability of choosing a white marble is:
If the amount of time taken to go said distance is x and the amount of time taken to go back said distance is y, then the amount of miles total is 7x+3y due to that for every hour, she adds 7 miles when going there and 3 miles for walking back. In addition, since the total amount of time is 4 hours, x+y=4 as the total time spent as well as 7x=3y due to that they're the same distance.
x+y=4
7x=3y
Dividing the second equation by 7, we get x=3y/7. Plugging that into the first equation, we get 3y/7+y=4=10y/7 (since y=7y/7). Multiplying both sides by 7 and then dividing both by 10, we get 28/10=2.8=y in hours. Since 0.1 hours is 60/10=6 minutes, and 0.8/0.1=8, 6*8=48 minutes=0.8 hours, meaning that she should plan to spend 2 hours and 48 minutes walking back
The true question should be like this:
<span>What is the center and radius of the following circle: x^2 + (y _ 6)^2 = 50,
circle quation formula is (x-a)^2 + (y-b)^2 = R², so by identifying each term, we find </span>(x-a)^2=x^2 = (x-0)^2, (y-b)^2= (y _ 6)^2, R² = 50, implies R =5sqrt(2),
it is easy to identify that the center is (a,b)= (0, 6)
the radius is R =5sqrt(2),
Using the distributive property, you can distribute the 7 to y and -4. In other words, multiply the number outside of the parenthesis by each of the numbers in the parentheis.
7*y+7*-4
=7y-28
:)