a) 2 kg water and 0.5 kg kerosene oil
b) 2.5 kg water and 1.5 kg kerosene oil
c) 1 kg water and 0.5 kg kerosene oil
d) 1.5 kg water and 2.5 kg kerosene oil

Answer: c
Explanation: The cooling system should be cleaned at suitable intervals to remove Rust and Scale. One kg of washing soda and 0.5 kg of kerosene oil should be added to 10 kg of water to make a solution. The radiator should be filled with such solution and be allowed to remain there for 8 to 10 hours. After this, the engine should be started and run on medium speed. After 15 to 20 minutes the solution should be drained out.