Chair and table patterns

This task is about continuing patterns.

Question 1Change answer

a)  In a room, five chairs are put around one table, as shown.
     
 
When two tables are joined, six chairs will fit.
     
 
When four tables are joined, ten chairs will fit.
How many chairs will fit around six tables joined together in this way?  chairs

Question 1Change answer

b)  In a restaurant, four chairs are put around one table, as shown.
     
 
Six chairs can be put around two tables joined together in a row.
     

 
Eight chairs can be put around three tables joined together in a row.
     
 
The restaurant needs to join 20 tables together in one long row.
How many chairs can be put around 20 tables joined together in a row?  chairs