A solid brass sphere of radius 2.1 dm is converted into a right circular cylindrical rod of length 7cm. The ratio of total surface areas of the rod to the sphere is
Present ages of Rahul and his brother are in the ratio of 5 : 3. After 4 years ratio of ages of Rahul’s brother and his sister will be 5 : 6. If the present age of his sister is 26 years, then what will be the age (in years) of Rahul 3 years from now?