Varun Chopra

How do i solve this: A die is thrown again and again until three sixes are obtained. Find the probability of obtaining the third six in the sixth throw of the die ??

Well, I have a question that might sound a little out of context. But I am quite curious about it. Just the other day I was helping my son with his EVS chapter-Air we breathe. My question is that if the air we breathe contains many other gases (apart from oxygen) then how does our body take in only oxygen. In other words, how does it filter other gases?

Curiosity is good, It adds to children's personality................ Now about your question The air we breathe is made up of several gases. Oxygen is the most important for keeping us alive because body cells need it for energy and growth. Without oxygen, the body's cells would die. Carbon dioxide is the waste gas that is produced when carbon is combined with oxygen as part of the body's energy-making processes. The lungs and respiratory system allow oxygen in the air to be taken into the body, while also enabling the body to get rid of carbon dioxide in the air breathed out. Respiration is the term for the exchange of oxygen from the environment for carbon dioxide from the body's cells. If the air you breathe is dirty or polluted, your respiratory system filters out foreign matter and organisms that enter through the nose and mouth. Pollutants are breathed or coughed out, destroyed by digestive juices, or eaten by macrophages, a type of blood cell that patrols the body looking for germs to destroy. Tiny hairs called cilia protect the nasal passageways and other parts of the respiratory tract, filtering out dust and other particles that enter the nose with the breathed air. As air is inhaled, the cilia move back and forth, pushing any foreign matter (like dust) either toward the nostrils, where it is blown out, or toward the pharynx, where it travels through the digestive system and out with the rest of the body's waste.