The age of Sitamma 10 years ago was thrice the age of Radha. 10 years hence, Sitamma's age
will be twice that of Radha. What is the ratio of their present age ?

let Radha age 10 years ago be x 

and sitamma age 10 years ago is 3x

so now 10 years hence the age of radha is x+10+10 = x+ 20

similarly age of sitamma is 3x + 20 

we know 10 year hence the age of sitamma is twice the age of radha

3x + 20 = 2(x +20)

so x = 20

therefore age of radha 10 years ago was 20 and that of sitamma was 60 

hence the present age of radha is 30 and that of sitamma is 70 

therefore the ratio of sitamma and radha's age is 70:30 i.e 7:3