Answer:
3/8
Step-by-step explanation:
3/4 x 1/2 = 3/8
 
        
             
        
        
        
Answer:
a.) 4 half lives have passed
b) 9.388 minutes
Step-by-step explanation:
Formula for exponential growth / decay is given as:

Where  is the final population
 is the final population
 is the initial population
 is the initial population
 is the growth factor
 is the growth factor
 is the time taken for the growth 'b'
 is the time taken for the growth 'b'
 is the amount of time
 is the amount of time
Here, we are given that:
 = 6. 9 grams
 = 6. 9 grams
 = 110.4 grams
 = 110.4 grams

 min
 min
To find:
a.) Number of half lives taken for the decay.
b.) Total time in the decay.
Solution:
a.) Number of half lives taken for the decay is nothing but equal to  .
.
Putting the values in the formula, we get:

Therefore, the answer is:
<em>4 half lives </em>have passed.
b.) Total time of decay. We have to find the value of  here.
 here.
From answer of part a.):

 
        
             
        
        
        
It would be around 9.304. so you'd round to the nearest tenth 9.3
        
                    
             
        
        
        
D, or 100/20. its traveling 5 meters per second.