You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Weight of newborn doubles by what age ? and explain in detail?
O.P. Ghai 9th edition - page 13. "An infant usually doubles his bih weight at the age of 5 months. The bih weight triples at 1 year and is 4 times at the age of 2 years. Thus, the weight at 5 months, 1 year and 2 years is 6, 9 and 12 kgs, respectively."