Answer:
She would need at least 11 buses leaving 17 spare seats.
Step-by-step explanation:
171+22+13= 206
206/20= 10.3
10.3 = 11
 
        
             
        
        
        
Equation for this problem:            Total 3 cubed / (L x W)
So 18.5cm x 15cm = 277.5 is the product of L and W. Now you need to devide the total by 277.5 which is 14. So the aquarium is 14 cm deep.
 
        
             
        
        
        
Answer:
An odd number is any number than can't be divided by two ! Some examples are 1, 3, and 5.
 
        
                    
             
        
        
        
Step 1. Multiply first equation with -3 and the second one with 2. You'll get:

Step 2. Add both equations together. You'll get:

, which gives x = -2
Step 3. Replace x = -2 in the first equation and calculate y.

The solution is: x=-2, y=5
 
        
        
        
Represent the unknows with n and d.
Then n+d = 44 (# of coins)
and 
$0.05n + $0.10d = $3.10   (value of coins)
Solving the first equation for n, we get n = 44-d.  Subst.  44-d for n in the 2nd equation:
0.05(44-d) + 0.10d = 3.10
Then 2.20 - 0.05d + 0.10d = 3.10, or
          2.20 + 0.05d             = 3.10, or    0.05d = 0.90.  Solving for d, 
       0.90
d = -------- = 18
        0.05
There are 18 dimes and 44-18 nickels.  How many nickels is that?  ;)