Warm ocean surge or Peru current that recurs after 5-8 years in East pacific along south America is

Warm ocean surge or perucurrent that recurs after 5-8 years in East pacific along south-America is

The ages of Sulekha and Arunima are in the ratio of 9:8 respectively. After 5 years eth ratio of their ages will be 10:9. What is the difference in their ages? a. 8 years b. 5 years c. 6 years d. 7 years e. none of these