Answer:
1 N 3
Step-by-step explanation:
 
        
             
        
        
        
The general way to work this out is to solve the general expression for 
the remaining quantity versus half-life, using logarithms.  But that's not 
necessary with these numbers.
Look at the numbers:
-- 3 mg is  1/4  of  12 mg.
-- 1/4  is the product of  (1/2) x (1/2).
-- So the  3 mg is what's left of  12 mg after  2  half-lives.
The  26  minutes must be two half-lives.
-- The half-life of that substance is  26/2 = <em>13 minutes</em>.
Go Maggie !
        
             
        
        
        
The answer is X-2 ........
        
                    
             
        
        
        
Answer:
The ones that can be used are (B and A) 
The ones that cannot be used are (C and D)
Step-by-step explanation:
Because the panthers got 6 less and the tigers got 22…
b+6 would make 22 (panthers plus 6 makes tigers)
22-b would also be 6 because 6+b makes 22, so subtracting b from 22 makes 6