Six years hence, the difference between Promila's and Sakshi's ages will be 9 years, and because the age difference remains constant over time, their present age difference is also 9 years. One year ago, Promila was 4 times as old as Sakshi, meaning the difference between their ages at that time was 3 times Sakshi's age one year ago. Setting 3 times Sakshi's age equal to 9 years shows Sakshi was 3 years old one year ago, making her present age 4 years and Promila's present age 4 plus 9, which is 13 years. The ratio of their present ages is therefore 13 to 4.