Answer:
It is the top left one
Step-by-step explanation:
 
        
             
        
        
        
Find the rate in which both balls make one full rotation around the track.
Ball A:

It takes 30 seconds for Ball A to make a full rotation.
Ball B:

It takes 20 seconds for Ball B to make a full rotation.
Find the least common multiple of 20 and 30 to find the time at which they'll meet.
Multiples of 20: {20,40,60}
Multiples of 30: {30,60}
60 is the least common multiple of both 20 and 30.
The balls will meet again at 
60 seconds.
 
        
        
        
Answer:
the act or process of forming a solution. the state of being dissolved (esp in the phrase in solution) a mixture of two or more substances in which one or more components are present as small particles with colloidal dimension; colloida colloidal solution. a specific answer to or way of answering a problem.
( I hope this was helpful) >;D 
 
        
             
        
        
        
Answer:
They let you know the number of numbers there are/will be.
Step-by-step explanation:
Mono, being one, means there will only be one number is the equation.
Bi, being two, means there will be two numbers in the equation.
and tri, being three, means there are three numbers in the equation.
 
        
                    
             
        
        
        
The answer is A. 41 because it is in the middle of the box.