Encik Zali works as a computer programmer in a computing firm. In October 2019, he purchased 30 units of used computers from a computer supplier for RM 10,000. He borrowed RM 9,000 from his sister. With the help of his brother-in-law, a computer technician, they repaired and upgraded the computers. Encik Zali then put up an advertisement to sell the computers in the Malay Mail for two weeks. He also asked his friend who is studying in a private college to help him to sell the computer with a promised 5% commission. By the end of December 2019, he managed to sell all the 30 units. He repaid his brother-in-law and his friend for their contribution. As a result, he made a profit of RM 15,000. 

Required: Explain with reasons, whether the profits arising from the above transactions are liable to income tax.