Present ages of Deepa and Hyma are in the ratio of 5:6 respectively. After four years, this ratio becomes 6: 7. What is the difference between their present ages?

Let the present age of Deepa = 5p

Let the present age of Hyma = 6p

After four years their ratio = 6 : 7

=>  $\frac{5p + 4}{6p + 4} = \frac{6}{7}$

=> 35p + 28 = 36p + 24

=> p = 4

Therefore, the difference between their ages = 24 - 20 = 4 years.