# A Pre-RMO question! -11

Probability Level 1

In a University out of $120$ students, $15$ opted mathematics only, $16$ opted statistics only, $9$ opted physics only and $45$ opted physics and mathematics, $30$ opted physics and statistics, $8$ opted mathematics and statistics, and $80$ opted physics.

Find the sum of number of students who opted mathematics and those who didn't opted any of the subjects given.

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