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:

 
        
             
        
        
        
A² + b² = c²   a and b are the legs and c is the hypotenuse.
7² + 24² = c²
49 + 576 = c²
625 = c²
√625 = √c²
25 = c
hope that helps, God bless!
        
             
        
        
        
1. 8+5=13
2. 13 x 3 x 10 = 13 x 30 = 390
Using the information above transform the ratio 8:5.
8 x 30 : 5 x 30
If you do this, you'll end up with the ratio:
240 : 150
This means that 240 adults attended whilst 150 children attended.
        
             
        
        
        
Answer:

Step-by-step explanation:
If that is a square, then all sides are the same. Therefore, it's a  by
 by  shape. We'll use Pythagorean Theorem to find the diagonal.
 shape. We'll use Pythagorean Theorem to find the diagonal.

Since it's not a fraction, there is no denominator to rationalize. Let me know if you have any other questions!