Step-by-step explanation:
Simple 
We will subtract 
21 - 16 = 5 
So 5 more students can join the class
 
        
             
        
        
        
Answer:
15/100
Step-by-step explanation:
 
        
                    
             
        
        
        
30 
It’s a word problem for LCM
3 x 10 which will give you the lowest common multiple (LCM) also giving you the lowest number of clusters