A mixture contains acid and water in the ratio of 7 : 3. If 4 litres of water is added to it, then the ratio of acid and water becomes 7 : 4. What is the quantity (in litres) of acid in the mixture?
The average height of A, B and C is 148 cm. If the average height of A and B is 136 cm and that of B and C is 125 cm, then what is the height (in cm) of B?
The volume of a right circular cone, whose radius of the base is half of its altitude, and the volume of a hemisphere are equal. The ratio of the radius of the cone to the radius of the hemisphere is
P and Q undertook to do a work for Rs 7200. P alone could do it in 20 days and Q alone in 12 days. With the assistance of R they finished the work in 5days. What is the share (in Rs) of R?