Let ‘x’ be the maximum marks in the examination.

Therefore, Peter got 30% of x =  = 0.3x
And Paul got 40% of x =  = 0.4x.
In terms of the maximum marks Paul got 0.4x – 0.3x = 0.1x more than Peter. — (1)
The problem however, states that Paul got 15 marks more than the passing mark and Peter got 10 marks less than the passing mark. Therefore, Paul has got 15 + 10 = 25 marks more than Peter. — (2)

Equating (1) and (2), we get
0.1x = 25 => x =  = 250
‘x’ is the maximum mark and is equal to 250 marks.

We know that Peter got 30% of the maximum marks.

Therefore, Peter got  = 75 marks.

We also know that Peter got 10 marks less than the passing mark.

Therefore, the passing mark will be 10 marks more than what Peter got = 75 + 10 = 85.