Correct Answer - Option 3 : 61

**Given:**

Average of six subjects = 75

Average of seven subjects = 73

**Formula used:**

Average = Sum of values/number of values

**Calculation:**

The average marks of a student in six subjects = 75

The sum of marks of a student in six subjects = 75 × 6

⇒ 450

The average marks in seven subjects, including Maths = 73

The sum of marks of a student in seven subjects = 73 × 7

⇒ 511

Marks scored in Maths = The sum of marks included maths - the sum of marks with out Maths

Marks scored in Maths = 511 - 450

⇒ 61

**∴ Marks scored in Maths is 61.**