Some families went on an outstation tour. The given histogram shows their ages.

What is the ratio of the number of persons of age less than 15 years to that of persons of age less than 30 years?

3 : 7

number of persons of age less than 15 years  :   Number of persons of age less than 30 years

( 2 + 7 + 6 )  :  ( 2 + 7 + 6 + 7 + 9 + 4 )

        15         :           35 

         5          :            7