Answer:
39,000
Step-by-step explanation:
 
        
                    
             
        
        
        
The answer is the first one 
        
             
        
        
        
Answer: 0.8(.50)^t/5
Step-by-step explanation:
P(t)= p^0(1+-r)^t
0.8= initial mass
.50= 100/2-> halving
t/5= how many times for every 5 days
 
        
             
        
        
        
Answer:
it is the second one 
Step-by-step explanation: