From the following table, how many patients were in the age group 40-…

 Age(years)

 less
 than 10 

 less
 than 20 

 less
 than 30 

 less 
than 40 

 less
 than 50 

 less
 than 60 

 less
 than 70 

 No. of patients 

11

15

22

29

35

45

50