Question

there are 180 multiple choice questions in a test a candidate gets 4 marks for every correct answer and every un attempt or wrongly answer question one mark is dedicated from the total score of correct answer if the candidates code for 450 marks in test how many questions did he answer correctly

Answer 1

Hiiiii....
Here is your answer......

Let, correct answers = x
wrong answers = y
Solution :-
Condition 1 : x+y=180..........................(1)
Condtion 2 : 4x-y=450........................(2)
By adding eq. (1) and (2)
x+y=180
4x-y=450
By eliminating +y and - y
5x=630
x=630/5
x=126
Place x=126 in (1)
x+y=180
126+y=180
y=180-126
y=54
Result:-
Correct answers = x = 126