Answer:
feldspar, because it has a higher number then gypsum and apatite, and it can be scratched by quartz because it has a lower number. 
 
        
             
        
        
        
The answer to your question is D
        
             
        
        
        
The correct answer is A, if you use photomath you can usually find the answers to most algebra problems
        
             
        
        
        
2500 * 0.9 = 2250
2250 * 0.9 = 2025 current stock