A) 8 chocolate chip cookies
B) The ratio of sugar to oatmeal is 2:3 because there are 12 sugar and 18 oatmeal. 12/18 simplified is 2/3.
        
             
        
        
        
Step-by-step explanation:
if 900 is increased by 20% then
120/100×900=1080
Decreasing it by 20% then
80/100×1080=864
 
        
             
        
        
        
Answer:
$500 is the original price
Step-by-step explanation:
0.6x = 300         Divide 0.6 on both sides
      x = $500
 
        
                    
             
        
        
        
No offense but this is really easy all you do is substitution
(2+3)= 5
        
                    
             
        
        
        
Answer:
<em>9*364 - 9*125 - 9*39 = 1,800</em>
Step-by-step explanation:
<em>Mental Calculation</em>
If we detect known patterns in the calculations, we could easily give their results without the use of calculators.
We are given the expression to evaluate:
9*364 - 9*125 - 9*39
The first thing to note is the 9 is a common factor of all terms, thus we take it out:
9*(364 - 125 - 39)
The negative numbers can be easily added
      125
+     39
------------
      164
Now our expression is much easier:
9*(364 - 164)
The subtraction of 364-164 is 200, thus the result of the operations is:
9*200. We only need to recall 9*2=18 and add two zeros to get 1,800, thus:
9*364 - 9*125 - 9*39 = 1,800