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A car is crossing a 20km long bridge. The bridge can support at most
1500kg of weight over it. If somehow, the weight on the bridge becomes
more than that, it will break.
Now, the weight of the car is exactly 1500kg. At the midway, a bird
comes and sits on the roof of the car. This bird weighs exactly 200
gram.
Can you tell if the bridge breaks at this point or not?
Read what will happen next?
Source
What was the situation?
At first look, the first impression would be that the bridge will break certainly. But if you wait for a while before concluding anything you will get the right answer.
The bridge will not break in the case! It's 20 km long bridge & now it's in the middle of bridge after traveling 10 km. By now, it must have used half of the fuel that was in the tank initially at the start. This amount of fuel must be weighing more than 200 gm. Hence even a bird sits on the car there are hardly any chances the total weight on the bridge goes beyond 1500 kg! Hence, no chance of breaking of it.
Suppose we lay down two cups in front of you. One of the cups is filled
with tea and the other one with coffee. Now we ask you to take a
spoonful of tea and mix it with the coffee.
At this moment, the coffee
cup has a mixture of tea and coffee. You have to take that mixture
(spoonful) and add it back to the tea.
Can you now tell if the cup of coffee has more tea or the cup of tea has more coffee ?
Skip to the answer!
Source
How mixture made?
After adding 1 spoon of tea into coffee, the levels of liquids in both cups must be unequal. Whatever now tea cup is missing is now in cup of coffee & mixed with coffee. The content of tea in the cup of coffee is certainly more.
Now after taking spoonful of the mixture back to tea cup the levels of the liquid in both cups would be same. Hence, whatever the cup of tea is missing is replaced by coffee. That missing tea content is now in the cup of coffee where it has replaced some of coffee content!
Suppose there are 1000 molecules in each cup i.e. of tea & coffee. Let's assume 100 molecules of tea are mixed to coffee using spoon. Now, coffee cup will have 1100 molecules and tea will have 900 molecules. Obviously, right now the cup of coffee contains more tea (100 molecules) that coffee in cup of tea (0 molecules)!
Now while taking 100 molecules back from mixture having 1100 molecules, suppose 70 molecules of coffee & 30 of tea are taken. That means, exactly 100 - 30 = 70 molecules of tea left in mixture. That 70 + 30 molecules mixture is poured into cup of tea. That is exact 70 molecules of coffee mixed in tea.
What does it mean? 70 molecules of coffee have displaced 70 molecules of tea into cup of coffee maintaining level of both the liquids.
We can say other way as well. 30 molecules of tea displaced 30 molecules of coffee into cup of tea while maintaining levels of both the liquids same.
So the answer is both have same level of contents mixed.
One day, a class teacher was told that the school superintendent will be
visiting her class on the next day. The superintendent can ask
questions from anywhere and it can be easy as well as difficult. The
teacher will have the liberty to choose any pupil for answering the
question.
Now she is determined that the impression that is cast upon the
superintendent after the inspection should be great. How will she
instruct the students so that she maximizes the chances of receiving a
correct answer for each question? Also, she must create the best
impression. How will she do it?
This is what she should do!
What was the resolution of teacher?
Now what should teacher do here is to devise the 'sign' language to communicate with students. Also she needs to make sure that the superintendent won't have any doubt while questioning students.
She should ask all the students to raise hands for every question that is being asked by superintendent. However, those who know correct answers should raise right hand & rest of all should raise left hand. This way she would be able to know the students who knows the correct answer & choose any of them to answer the question.
All raised hands to each question would definitely leave great impression on the superintendent.
Note : We are assuming superintendent not smart enough to notice that students raising different hands for different questions.
A devotee visits 9 temples when he visits India. All these nine temples
have one thing in common - there are 100 steps in every temple. The
devotee puts Re.1 coin after climbing up every step. He does the same
while climbing down every step. At each temple, the devotee offers half
of his money from his pocket to god. In this way, his pocket becomes
empty after his visit to 9th temple.
Can you calculate the total amount he had initially ?
Click here to know exact amount!