"Pranay suffered from measles at the age of 10 years. There are rare chances of his getting infected with the same disease for the rest of his life." Give reasons for the statement

A boy of ten years had chicken pox. He is not expected to have the same disease for the rest of his life. Mention how it is possible.

Raman went to a hospital with his father to see his uncle who was admitted there because of some health problems. The doctor asked Raman to bring a particular injection to be given to his uncle. When Raman brought the injection, the doctor asked him to get the injection changed from the chemist. Raman insisted that it was the same injection as prescribed by him and its expiry date is also next year. But the doctor explained Raman that the injection has not been expired but it was not of compatible concentration as prescribed by him. Raman felt satisfied and got the injection changed Answer the following questions: What was the reason for asking Raman to get hte injection of compatible concentration?

A farmer harvests his crop and expresses his harvest in three different ways: (a) I have harvested 10 quintals of wheat. (b)1 have harvested 10 quintals of wheat today in one acre of land. (c) I have harvested 10 quintals of wheat in one acre of land after 6 months from sowing. Do the above statements mean one and the same thing. If your answer is yes, give reasons. And if your answer is 'no' explain the meaning of each expression.