To calculate KCET qualifying marks when your board exam scores are out of 90 in Physics and Chemistry instead of 100, you need to convert your board scores to a 100-point scale. This is typically done by calculating the percentage of marks obtained and then scaling it to a 100-point system.

Here's how to calculate the qualifying marks:

Calculate the total PCM marks for your board exams: Add your scores in Physics, Chemistry, and Mathematics.

Divide the total PCM marks by the total possible marks (300): This will give you the overall percentage of your board scores.

Multiply the percentage by 100: This will convert the percentage to a 100-point scale.

Consider the 50:50 weightage: Your final rank in KCET will be based on your KCET score (50%) and your board marks (50%).

Example:

If your board scores in Physics and Chemistry are out of 90 each and Mathematics is out of 100, and you scored 80 in each subject, here's how you would calculate the qualifying marks:

Total PCM marks: 80 (Physics) + 80 (Chemistry) + 80 (Mathematics) = 240

Percentage of board scores: (240 / 300) = 0.80

Scaled board scores: 0.80 * 100 = 80 (out of 100)

Your board marks would be treated as 80 out of 100 for the KCET rank calculation.