Sonam's age after eight years will be half of her father's age. Eight years ago the ratio of their ages was 1 : 3. Find the present age of Sonam's father.
Rahul can complete a work in 18 days and Sonu can complete the same work in 15 days. If both together work for 5 days, then what part of total work is left?
Before Champaran Satyagraha, the farmers of Champaran used to follow the 'Panchkathiya' system, whereby five katthas of land in a bigha had to be planted with ___.