Half of the total members are men. For every on women there is one man.
So if there was a total of 100 people in the library and the ratio of man to women was 1:1 there would be 50 women and 50 men. 
        
             
        
        
        
Answer:
N = 140 
Step-by-step explanation:
N/7 = 20 
Inverse operation of division: multiplication
N/7 = 20 
becomes: 
N = 7 x 20 
N = 140 
Thus, the value of N is 140. 
 
        
             
        
        
        
A = {0, 1, 2, 3}
C = {0, a, 2, b}
A ∩ C = {0, 2} → E)
A set of the same elements from the set A and the set C.