Answer:
2,800 Books to be the same.
 
        
             
        
        
        
Answer:
it will take her an hour and 25 minutes roughly
Step-by-step explanation:
 
        
             
        
        
        
Answer:
These two figures are similar because  equals
 equals 
Step-by-step explanation:
The figures will be similar if their ratios of the two sides are equal. So we need to check the ratios of the figures to see if they are similar or not.
For the smaller figure the ratio is  , and for the bigger figure the ratio is
, and for the bigger figure the ratio is  which upon simplification reduces to
 which upon simplification reduces to   .
. 
So we see that the ratios are equal. Thus the figures are similar.
 
        
             
        
        
        
Density is the degree of compactness of a substance. It is the degree of consistency measured by the quantity of mass per unit  volume. It is the relationship between the mass of the substance and the amount of space it takes up. I hope it helps.