Your younger brother is a book-worm. He has gone to stay in a hostel. Write a letter to him advising him to take part in games and other school activities. 

Dear Manoj, 
I have come to know from a friend of yours that you have become weak and are keeping indifferent health. You work hard at studies and have become a book-worm. You do not take part in games. 

I may tell you that a student must take care of his health also. His mental and physical development should go hand in hand.

All work and no play makes Jack a dull boy. A sound mind lives in a sound body. Games can teach us even more than books do. They can make us active and strong. So make it a point not to neglect games. Play regularly so that you may do well in studies also. 

I hope you will act upon my advice and start taking part in games. 

Your loving brother,