Write a letter to your younger brother wishing him good luck for the examination.
My dear brother,
I hope you are having a great time in Bangalore. After reading your letter, I came to know that your examination is going to start from 15th of next month. Through this letter, I am writing to you to wish you very good luck with your examination.
I know about your dedication and commitment to your studies. Undoubtedly your efforts will pay off. You are a very hardworking student and I believe that you will achieve extraordinary grades and bring honour to our parents. Just to say you should be very calm and try to answer all the questions carefully. Always remember that success is just one step away from you.
I wish you the best of luck for your examinations. May your hard work be rewarded with the success you truly deserve.