Hey Divya

Solution (S):

S = 0.7+0.77+0.777+....0.7777

=7(0.1+0.11+0.11+0.111+.......+0.1111....)

= 79[0.9+0.99+0.99+0.999+...........)

=79[(1−0.1)+(1−0.01)+....+(1−0.000......1)]

=7/9 * [20 − (1 / 10+1 / 10^2+......1 / 20^20)]

Therefore, a= r = 1/10

=7/ 9* [20−1/9 * (1−10^−20)

=7 / 81 * [179 + 10^−20]  -> Answer

Hello!!!

Hope you are doing great!!!

Given series = 1+3/2+5/4+7/8.........

=1+3/2+5/4+7/8+9/16+11/32+..........

multiply and divide by 2

=2(1+1/2+1/4+1/8+1/16+1/32+............)

=2+2(1)+2(1/2)+2(1/4)+2(1/8)+2(1/16)+..................

2+2(1+1/2+1/4+1/8+1/16+..............)

here (1+1/2+1/4+1/8+1/16+..............) is in GP

The value of (1+1/2+1/4+1/8+1/16+..............)=2

substitute in the above equation

=2+2(2)

=2+4

=6

Hope it helps you!!

Thank you!!!

You have almost 1 year to appear for JEE main January exam you can follow the following tips to do well in the exam.

• If you feel your physics is weak then start by developing concepts it is a proven fact that most of the aspirants start by following HC Verma so I strongly recommend you to switch to HC Verma for physics the book is very well written and easy to understand solve all the problems.
• previous year papers are very helpful for scoring good marks in JEE main and will also help you to understand the important topics which are frequently asked in exam.
• you should be fully aware of syllabus and while reading you should be specifically mark it whether this particular topic is from the syllabus and how much questions are asked on that particular topic from the previous years.
• The fact is that there are certain topics which have higher question chances to occur then the other but at the same time it is also that almost all the topics are asked in the exam there for want leave any topic.

Ifyou follow the other mention tips when you have lot of time and can improve open your pic topics is you mentioned physics and can work upon it to excel in the exam.

Hello Subhodeep

There are several books, you may consider any of the below mentioned:

Organic Chemistry by O P Tandon, NCERT, NOOTAN Chemistry, etc.

For more list of good and recommended books for JEE please refer the below mentioned link:

https://engineering.careers360.com/articles/best-books-for-jee-main

Hello dear student,

I understand what you are trying to ask and that can only be achieved with consistent solving questions. Nothing can help you to improve your speed  but your practice to solve mcqs now . Set a clock with timer of one hour or 30 mins . Take a topic and give one minute to one question. If you are setting your clock with one hour timer then take 60 questions and likewise if 30 mins take 30 questions of a topic or multiple topic. That will help you build the concept of a topic plus this will help you to improve your speed to solve questions. I hope this was helpful to you.

Best wishes

Hey there

Physics is tough do not think it's your fault. It will sound weird but if you want your physics strong then get a good teacher for you. Then after each topic he teaches you do not jump directly to JEE level try to first understand the theory and then practice HC Verma. HC Verma is the best book imfor physics. Try thinking about the problem and do not leave any doubts. Try to learn a concept and apply it to as much problem as you can it will increase your thinking.

Good luck

Hey there

C++ is a very interesting language to learn in order to get hands on c++ you should start learning it from YouTube or any other means. Then practice it on dev++ etc. For book you can refer yashwant kanetkar it is one of the best book for semesters.

Good luck