Question

Let the no.of correct answers be x. Then no.of wrong or unattempted answers be 180-x. Then equation becomes
4x-1 (180-×) = 450.

Answer 1

4x-1 (180-x) = 450
(720x-3x)-(180-x) = 450
717x-180-x =140
717x-x-180=140
716x-180=140
716x=140+180
716x=320
x=320/716
x=2.2375