In a test , 4 marks are given for every correct answer and -2 for every wrong answer .Rohit answered all questions and got 68 marks.25 of Rohit's answers were correct. How many of the questions he attempted were incorrect ?

Rohit answered all questions.

Correct ans. by Rohit = 25.

Each correct ans. = 4

So Rohit got = 25 * 4 = 100 marks.

But Rohit got 68 marks in the test.

Each incorrect ans = -2 marks.

So no. of incorrect ans. given by Rohit = (100 - 68)/2 = 32/2 = 16 Ans.