The average marks obtained in a test by three students is x. If the marks of a new student is also considered, then the average marks increases by 2. What is the marks secured by the new student in the test?

x + 8

Sum of marks of 3 students = 3x

New students is added , Sum of marks of 4 students = 4 × ( x + 2 ) 

3x + Marks of new students = 4x + 8

Marks of new students = 4x + 8 - 3x = x + 8