Tamim Ahmed

I'll give you a review. About me: I went to nationals for student congress (essay writing/speech giving) here in the USA and I've won dozens of scholarships based on essay prompts.

I've gotten 5s on every GRE I have taken (3 of them).

Mistakes you've made: 
"the humanity", "profound impact" =>impacts, "of computer" => of the computer, "... in almost everywhere in the world" (this makes no sense) => in almost every corner of the world, "the statement mentions" statement => prompt, "As the world is developing day by day" (this makes no sense). -ing implies progressive tense (still occuring!) this means that as the world is changing day by day—you basically are saying 'As the world is changing day by day day by day',

... tbh you're making an insane amount of grammar mistakes. A 3 would be generous.
You assume I know what quantum mechanics is (you should always explain what aspect you're referring to). You write very short sentences which doesn't work with your writing style. Try and write more thorough paragraphs like your third paragraph. Your conclusion is decent. I'd assume it'd be paired with a 3 or 3.5, but your intro and second paragraph are really no good.
 
Here is a format you should focus on using: (I call this the FIRST/FURTHERMORE/FINALLY)
introduction include a nice introductory sentence that acts as an axiom/adage/aphorism briefly introduce 2 strong points.  Say how you'll analyze each point, then how you'll wrap them together Point 1("FIRST") "first, [point 1]" explain how it relates to the prompt on a philosophical level  "For example,..." explain how your point relates to a real example Point 2 ("FURTHERMORE") "first, [point 2]" explain how it relates to the prompt on a philosophical level  "For example,..." explain how your point relates to a real example Analysis ("All together, point 1 and point 2...") explain why these two points matter to the prompt interconnect these ideas with an example Conclusion ("Finally") summarize point 1. summarize point 2 summarize analysis and interconnectedness. This is a better way to write than the 3-point/5 paragraph answer because you only have to focus on two points, only two examples (or a couple if you're fast), you get more time on each example, each point, each analysis, and can create better transitions.

Make sure you use phrases they like to hear: "For example," "For instance," "Connecting the ideas,", "What this means to the big picture"... stuff that indicates YOU UNDERSTAND.

For what it is worth, I got a 5 on my writing, but here is what I thought given your writing sample.

"A great leader is that a person who can help his the people they lead in their times of distress not by showing superiority to them, but by... (finish the sentence, currently seems fragmented). A person learns leadership from his events in their (or early on in their) childhood. Childhood is the period which will determine what he they will do next in his next their life (awkward sentence and I am not really sure what you are trying to prove). So whatever he they learns in that time their childhood is very important for his their life. That's why he they should learn to help others from childhood not neglecting them and thinks to go forward."
I wont go through the rest of the writing, but basically there are a few things you need to keep in mind when writing on these prompts. Try your best to avoid spelling mistakes, there are a few of them in there. Sentence structure should be done so that the reader can clearly understand what your argument is and what you are trying to prove. The whole idea of these prompts are to force you to either poke holes in other's logic, or write what your opinion is and provide support for that opinion. You can do neither of them if you do not structure your sentences well. I know that 30 minutes is not a lot of time to really think about the prompt and still get a lot written down, but you need to really think about the prompt for about a minute and perhaps type out a quick outline of what your end goal of the essay is. When I took the GRE writing portion, I thought about what belief I wanted the reader to end with and how I was going to prove my opinion to them. So I knew that every paragraph needed to build on each other and further my point to the conclusion.
 
As an example, I would have an outline similar to this one for this prompt:
 
Intro: talk about what it means to be a leader What qualities does a leader have? Does cooperation belong in those traits? What does competition do? Do I agree with the prompt? 1st body: Pick the first trait and talk about how it fits in with my opinion 2nd body: Next trait that supports the first one and flows to the end point. 3rd....etc body: Continue the flow Conclusion: Sum up why all of those things make a great leader and supports my vision of what a leader really is. End the essay with some powerful statement that shows I am confident in my stance. I hope this helps. I really can not evaluate a grade of what you would probably get as I have never really evaluated essays before, but it would maybe be around a 3-3.5 currently?