Answer:
the answer is 3
Step-by-step explanation:
 
        
             
        
        
        
Answer:
9.0.
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
Total number of tables of first type       = 23.
Total number of tables of second type = 7
Step-by-step explanation:
It is given that there are 30 tables in total and there are two types of tables. 
Let's call the two seat tables, the first type as x and the second type as y.
 ∴                                             x + y = 30                        ......(1)
Also a total number of 81 people are seated. Therefore, 2x number of people would be seated on the the first type and 5y on the second type. Hence the equation becomes:
                                             2x + 5y = 81                        .....(2)
To solve (1) & (2) Multiply (1) by 2 and subtract, we get:
                                                       y = 7
Substituting y = 7 in (1), we get x = 23.
∴ The number of tables of first kind         = 23
   The number of tables of second kind   = 7
 
        
             
        
        
        
Let the number of rows be = r
Let the number of seats per row be = s
we know that the number of seats is 126.
So,  ..... (1)
    ..... (1)
As given, there are five more seats per row than the number of rows, so we can say that:

Putting this in equation (1)





r=-14 and r=9 (neglecting the negative value) we get r=9
And s=r+5 
so, s =9+5=14
Hence, there are 5 rows and 14 seats per row.