IS GUESSING IN EXAMINATION OK?

Toss a coin 100 times. You are likely to get head around 50 times. So there is a 50 % chance of getting a head or a tail. In other words, the probability of getting a head or a tail is 1/2. The range of probability is 0 (no chance) to 1(100% chance).

Suppose you toss a coin 3 times, what is the chance of getting a head in all the 3 throws. Here the multiplication rule comes to our help. This rule can be applied when the events are independent of each other. Just multiply the probability of the event 3 times.

total probability = 1/2*1/2*1/2=(1/2)^3 = 1/8 = 0.125

The probability of getting only heads 3 times consecutively is 1/8 or 1 in 8. That is , if 8 persons throw the coins 3 times, 'one' may get the head all the three times.

Let us assume that in a multiple choice question, there are 4 choices and one among them is correct. Guessing that correct answer has a chance of 1/4. If there are 10 questions, what is the probability of guessing all the answers right. We know by applying multiplication rule it is (1/4)^10 = 0.0000009536.

By taking reverse,
1/0.0000009536 = 104857

The chance is 1 in 100000. It means, if 100000 students write the 10 questions test, one may get all the answers right by guessing and not applying the knowledge. Hence the examination board is taking a safe bet.
That is why only three tries are allowed in a bank website for entering the password.
So do not take chance, use wisdom.

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THE EARTH, A SUPER ORGANISM

JOIN MY COURSE: "Become a programmer in a day with python" A man called 'love lock' (what a name) proposed a theory called Gaia theory, named after Greek Goddess. It says, "Earth is a self-regulating organism like a human being. The organic life in it interacts with in-organic matter and maintains atmosphere, temperature and environment". Hence the earth is still suitable for the life to thrive. Imagine, in a particular place, there are lot of flowers. Some flowers are white and some are darkly coloured. We know, white reflects light and heat while dark absorbs the same. White flowers can thrive in hot climate. But dark flowers requires cold climate. The absorption and reflection balances and the environment reaches average, warm temperature at which both the flowers can co-exist. This is the essence of "Gaia" theory. On our earth, the oxygen constitute 20% of the atmosphere. The oxygen level is always mai

THE PARABOLA

A jet of water shooting from a hose pipe will follow a parabolic path. What is the so special about parabola. Y= x^2 Draw a graph for the above equation. It will result in a parabola. This parabola is also called unit parabola. Any equation involving square will yield a parabola. Example: Y = 2x^2 +3x+3 (also called quadratic equation) X= 2 and -2, both satisfies the equation 4 = X^2. Parabolic equations always have two solutions. Any motion taking place freely under gravity follows parabolic path. Examples: An object dropped from a moving train, A bomb dropped from flying plane, A ball kicked upwards. If a beam of light rays fall on the parabolic shaped mirror, they will be reflected and brought to focus on a point. This fact is made use of in Dish Antenna, Telescope mirrors, etc. Inverted parabola shape is used in the construction of buildings and bridges. Because the shape is able to bear more weight. A plane

DISORDER IS THE "ORDER OF THE DAY"

Imagine a balloon full of air. The air molecules are moving randomly inside the balloon. Let us pierce the balloon with a pin. The air rushes out. Why should not the air molecules stay inside the balloon safely and ignore the little hole? That is not the way the world works. The molecules always "want to occupy as many states as possible". Hence the air goes out in the open to occupy more volume. The things always goes into disorder (entropy) and the disorder increases with time. The above statement is what we call "second law of thermodynamics". Consider a cup of coffee on the table. Suppose the heat from entire room flows to your cup of coffee, the coffee will boil and the rest of the room will freeze. Freezing means bringing things to order and arrangement. It violates the second law. Hence it will never happen. Hence heat must flow from high temperature to low temperature and not the other way. The air molecules in y

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