Question

Please answer this!!!!!

Answer 1

Please tell me if you have any other proof, I got this:

Solution:
Let the correct answers be x nos. & incorrect answers be y nos.
Then we can say that no. of questions = x + y ........(1)

Now according to the given conditions, we have
Actual Marks = x - 0.50y
Marks after interchanging = 0.5x - y

Since, Marks after interchanging = Actual marks - 90
Therefore, 0.5x - y = (x - 0.5y) - 90
or 90 = x - 0.5x + y - 0.5y
or 0.5x + 0.5y = 90
or x + y = 180 .........(2)

from (1) & (2), we can say that
The number of question in the test was 180.

Is it right?