4/5=24/30 and 4/6=20/30
So three easy fractions between these are 21/30=7/10, 22/30=11/15 and 23/30.
        
             
        
        
        
Are there any other numbers to this question? I will be glad to help.
 
        
             
        
        
        
the answer should be 24 because you can divide it into 2 shapes and solve them separately and add those products
 
        
             
        
        
        
I did this in my math the other day and the answer is octagon 
i think of it as this 'the more angles there are the larger the angles'
i hope i helped