Question
In a test comprising 200 questions, four marks are
awarded for every question answered correctly. The number of marks deducted for every question answered wrongly and for question left unattempted is 2 and 1 respectively. If a student got 80 marks in the test, then which of the following can be the number of questions solved wrongly by the students?Solution
Let the number of questions solved correctly be x Number of questions solved wrongly = y Number of questions left not attempted = z x + y + z = 200 …………… (i) 4x - 2y - z = 80 …………… (ii) Adding eq (i) and (ii), we get x = (280 + y)/5 Only, y = 120, will give an integer value of x .
- 16, 36, 128, 768, 6144, 61440 
- 1286, 1061, 865, 696, 560, 431, 331 
- 9 20 63 255 1285 7716 ...
- 16,22,30,45,52,66 
- 48, 73, 109, 154, 222, 303 
- 3 5 9 17 32 65 ...
- Find the wrong number in the given number series. 
 
 25, 36, 50, 68, 92, 120
- Find the wrong number in given number series. - 6490, 6377, 6294, 6211, 6138 
- Find the wrong number in the given number series, - 121, 130, 116, 139, 103, 148 
- Find the wrong number in the given number series. 
 
 7, 9, 16, 12, 25, 15, 36