There are 5 letters
there are 5 possibilities for the first letter, and 4 possibilities for the second letter after the first letter is used up
so 5 * 4 = 20 possibilities
        
                    
             
        
        
        
Answer:
Katie needs to pay $27.9.
Step-by-step explanation:
Given;
Cost of per foot = $2.25
Number of  flowers in her yard = 12.4 square foot
We need to find how much she needs to pay.
Solution:
Now we know that;

So for  = Cost for
 = Cost for  .
 .
By using Unitary method we get;
Cost for  =
 = 
Hence Katie needs to pay $27.9.
 
        
             
        
        
        
<em>40</em>
- Step-by-step explanation:
<em>2 + 10 = 24</em>
<em>2(2 + 10) = 2×12 = 24</em>
<em>3 + 6 = 27</em>
<em>3(3 + 6) = 3×9 = 27</em>
<em>7 + 2 = 63</em>
<em>7(7 + 2) = 7×9 = 63</em>
<em>5 + 3 = 40</em>
<em>5(5 + 3) = 5×8 = 40</em>
 
        
             
        
        
        
So a²+b²=c²
8²+15²=c²
64+225=c²
289=c²
±17=c
So c=17 or c=-17