Write a letter to your father requesting him to allow you to continue your studies instead of joining his business.
6, New Hostel,
I have just received your affectionate letter. You have advised me to work hard for my ensuing examination and to join your business after the Senior Secondary Certificate.
Father, I assure you I am working very hard. Our XII class examination is approaching fast. I am sure, I shall come off with flying colors.
As for joining your business, I disagree with you. I want to become an engineer and join some service as such. There are many ups and downs in business. A businessman is always in tension day in and day out as the bureaucrats are on his nerves. Market trends take a heavy toll on his nervous energy. In service, man has a fixed income and is carefree.
Even if I, later on, decide to join your business, I must at least be a graduate. An undergraduate has no place under the sun in the present world. I shall be able to run the business much better as a graduate than as an undergraduate.
Therefore, I hope you will kindly allow me to continue my studies after completing my senior secondary certificate.
With deep regards to mamma.