10 second SICI MAGIC TRICK 💀 #infinitesimal

Added: 2026-05-17

[00:00:00]I start sweating after seeing the CI's questions.

[00:00:02]We will solve this question in 10 seconds and it comes many times in your bank exam.

[00:00:05]See what the question is. The question says The Compound Interest on a Certain Sum of Money. The principal after 8 years and 16 years is ₹3500 and ₹7700. Meaning, on the same principal at the same rate of interest, after 8 years you get ₹3500 and after 16 years you get ₹7,700 interest. Ok? So you have to tell me what will be the sum of money? How much will the principal be? So look, consider that he was the principal. Ok?

[00:00:29]How much interest do you get on this principal in 8 years? So sir I get Rs 3500.

[00:00:34]Ok? Now tell me one thing, if I do n't change anything else and just look at the principal. If he gives ₹3500 in 8 years, then he will give ₹3500 in the next 8 years also. Ok? So look carefully. If I talk about the next 8 years again, then I should have got this ₹3500. Why?

[00:00:50]Why did this ₹3500 come? Because what will the principal do to me for another 8 years? Will give interest of Rs 3500. Right?

[00:00:56]Same interest is earned at the same time interval. So we saw that.

[00:00:58]Now you were told that it was 16 years, so look, how much does 8 years and 8 years add up to? It's been 16 years.

[00:01:05]How much total interest did you get in 16 years? 77 but if you count now it is only 7000. Meaning I got Rs 700 extra.

[00:01:10]Right? And he will get it too. Why?

[00:01:12]Because this is compound interest.

[00:01:14]What happens in compound interest? You get interest on interest. Right? So why did this 700 come? Because you got some interest 8 years ago. I got an interest of Rs 3500. On this you have got interest of Rs 700. In how much time? In 8 years.

[00:01:28]So if ₹3500 gives you ₹700 in 8 years, then what percentage does it give? Can I say 20%? Yes. This means, Sir, how much interest are you getting in 8 years? Getting 20% ​​of the principal.

[00:01:42]Right? So can I write that how much interest does this principal earn in 8 years? 20% which is 1/5 and what is the same thing giving you? I have paid Rs 3500. Ok? So if you cross multiply five from here, then anyone can tell you that 17500 will be the correct answer. That is option number B. So this is how you would try to solve this, what do you have here? Yes, if I ask you what is the rate of interest for one year? So for that you will need a scientific calculator. But that's why the examiner will not ask that. Because the rate of interest that you are saying in 8 years is 20%, that is nothing but that. 1 + R / 100 of ^ 8. Now if it is 20% then how much will you write? 6/5 To solve this we will need a scientific calculator. So the examiner does not ask that. This was extra infection. I have told you. If you people have understood this and it has become clear, if you are new to the channel then subscribe and definitely like the video. See you in the next sh. Until then, take care.