Question

CPT the ground?
In a class test (+5) marks are given for every correct answer and (-2) marks are given for every
incorrect answer and no marks for not attempting any question.
(a) 'A' scored 80 marks. If 'A' has got 20 correct answers, how many questions did 'A' attempt
incorrectly
(b) 'B' scores 0 mark in this test, though 'B' has got 10 correct answers. How many questions has
'B'attempted incorrectly?
(c) 'C' scores -5 marks by attempting 13 questions. How many questions has 'C' attempted
correctly and how many has 'C'attempted incorrectly?​

Answer 1

Answer:

A scores 80 marks in a test

so, 20 are correct

For correct answers = 5 marks

20. 5=100

Total = Correct+ Incorrect

Incorrect = Total - Correct

Incorrect = 80-100=-20

A gets 80 marks.

correct = 100,

Incorrect marks = -20

Incorrect answers = -20/-2=10

Incorrect answers = 10

B scores 0 marks in a test

10 correct answers

10. 5= 50

Incorrect = Total - Correct

0-50=-50

Incorrect marks = -50

Incorrect answers = -50/-2=-25

Incorrect answers -25

c scores -5 marks by attempting 13 questions

For one correct answer = 5 marks

for one incorrect answer = -2

To get -5 incorrect answer = 5

so 5. -2

Incorrect marks = -10

Incorrect answers= 5

Unattempted= Remaining questions

= 5. 0=0

C attempted incorrect answers= 5

so, 5. -2=10 marks.

Hope this helps you