Answer:
11.42 boxes
Step-by-step explanation:
For the first box bought, there is a 100% chance of getting a unique toy (since you still don't have any). E₁ = 1.
After that, there is a 4 in 5 chance of getting a unique toy from the next box, the expected number of boxes required is:

For the next unique toy, there is now a 3 in 5 chance of getting it:

Following that logic, there is a 2 in 5 chance of getting the 4th unique toy:

Finally, there is a 1 in 5 chance to get the last unique toy:

The expected number of boxes to obtain a full set is:

We need five sections of 20% to get 100%.
So all we need to do is times 20 degrees by 5.
20 x 5 = 100
So your answer is 100 degrees.
Hope this helped. Have a great day!
1. Vertex E is the center of the circle, A and B are on the circle.
2. Any angle with these properties (i. E is center, AE and AB are radii) is called a central angle.
3. Check the picture.
4. An important property of these angles is that the measure of the arc AB = m(AEB)
The correct answer is C) (5m^50 - 11n^8) (5m^50 + 11n^8)
We can tell this because of the rule regarding factoring the difference of two perfect squares. When we have two squares being multiplied, we can use the following rule.
a^2 - b^2 = (a - b)(a + b)
In this case, or first term is 25m^100. So we can solve that by setting it equal to a^2.
a^2 = 25m^100 -----> take the square root of both sides
a = 5m^50
Then we can do the same for the b term.
b^2 = 121n^16 ----->take the square root of both sides
b = 11n^8
Now we can use both in the equation already given
(a - b)(a + b)
(5m^50 - 11n^16)(5m^50 + 11n^16)