Helllo Mohd,

Eamcet is conducted for 160marks in total

The Qualify mark for Eamcet is 40.

Eamcet includes three subjects as known by you

To get min marks 

Score

20 in chemistry

20 in physics

35 in maths 

If you just want to qualify that means pass according to you 

Then.

Since chemistry is easy score 20here

If you are good at maths score 20 here

If you are good at physics then try to score 20 else try for alteast 10 marks.

Dear its very easy to score min qualifying Mark if you have a strategy and plan

Practice alot 

You will definitely pass

All the best

Good luck.