In the given Venn diagram, the ‘circle’ represents ‘ladies’, the ‘triangle’ represents ‘teachers’, and the ‘rectangle’ represents ‘unmarried persons’. The numbers given in the diagram represent the number of persons in that particular category.

How many married ladies are teachers?

3

The ‘circle’ represents ‘ladies’

The ‘triangle’ represents ‘teachers’

The ‘rectangle’ represents ‘unmarried persons’

Step 1 ) Look at the figure of  Triangle , circle and  rectangle

Step 2) Look at  number given in married ladies are teachers 

Step 3) By visual observations we conclude that 3  is the number which represents married ladies are teachers