Answer:
12 hours
Step-by-step explanation:
Let Theo's siste can paint a fence in x times 
Given.
Theo can paint a fence three times as fast as his sister can. Working together, they can paint a fence in 9 hours.

Apply cross multiplication

Theo’s sister to paint the fence in 12 hours.
 
        
             
        
        
        
 w x L  = 36 
w =  L- 5 
L x  ( L-5 ) = 36 
L^2 -5L -36 =0 
<span>Use the quadratic formula
L=  - b + radical b^2  - 4 (a)(c)  divided    2.a 
L= 5 + 13  / 2  = 18 /2  =9</span>
        
             
        
        
        
Answer:
Width = 40 meters
Length = 167 meters
Step-by-step explanation:
Let 
Width of the pool = x meters
Then 
Length of the pool = 4x + 7 meters
and 
Perimeter  meters
 meters
Hence,

 
        
             
        
        
        
B is the answer i hope it helps i