MHT CET Exam is an easy exam when it comes to the standard of the questions and tough when it comes to the time in which the student has to solve it. If you want to score better first thing is that you go thoroughly through the state board textbooks. After that:

FOR MATHS:

You need to practice maths through some reference books and I think as your teacher suggested Arihant publications are good for MHT CET.

For CHEM:

By my perspective you should read the board textbooks a lot of times so you get perfect in the organic and inorganic section. For the physical chemistry part I would suggest you to practice a lot of problems of the CET standard from a reference book. My score in 2017 MHT CET Chemistry was 41/50. and I had followed this strategy.

Good Luck!