Answer:
6kg pure copper and 30 kg 10% copper was mixed to give 36kg of 25% alloy 
Step-by-step explanation:
Here, we want to produce 36 kg of 25% alloy
Let the Pure copper be x kg while 10% alloy be y kg
Pure copper is simply 100% copper 
Thus;
x + y = 36 •••••(i)
Then;
100% of x + 10% of y = 25% of 36
= x + 0.1y = 9 •••••• ii)
From i x = 36-y
from ii, x = 9-0.1y
Equate both x 
36-y = 9-0.1y
36-9 = 0.1y + y
0.9y = 27
y = 27/0.9
y = 30 
x = 36-y
x = 36-30
x = 6 kg 
 
        
             
        
        
        
The answer is D but i could be wrong
        
             
        
        
        
Answer:
50 mg for (dex) and 500 (gua) 50 times 4 is 200 for dex for ml mg is something else though. Also 500 times 4 is 2000 ml. So now just convert.
Step-by-step explanation:
 
        
             
        
        
        
7 is a prime number, which means it can't be simplified. This fraction is already in simplest form, also because 25 and 7 don't have any common factors.
        
                    
             
        
        
        
The distributive property of 18(12), or simply 18 * 12, is 216. (This is your answer.)