When a student score 35% marks, he fails by 15 marks. But when he scores 42% marks he got 20 more marks than passing marks. Find passing percentage.

38% 40% 35% 42%

38%

Let total marks = x ATQ,    x × (42 - 35) % = 15 + 20 = 35                      x   = 500 35 % of 500 = 175 (He fails by 15 marks so passing marks are 175 + 15 = 190) Passing percentage = \(\frac{190}{500}\) × 100 = 38 %