25 in exponential form:  
Factors to make 25 in exponential form: 5 * 5 = 5^2, 1 * 25 = 25^1
 
        
             
        
        
        
If I could see the photo I could help you answer the question
        
                    
             
        
        
        
31/50
31 ÷ 50 = 0.62
0.62 x 100 = 62%
So the answer is 62% 
Hope this helps I didn't know if the 7k was apart of the problem or a typo
        
                    
             
        
        
        
The greatest common factor of those numbers is 8.