In a class test containing 15 questions 4 marks are given for every correct answer and -2 marks are given for every incorrect answer.
(a) Teena attempts all questions but only 10 of the answers are incorrect what is her total score?
(b) One of her friends scored -4 marks in this test though she has got 8 correct answers. how many questions has she attempted incorrectly?
Answers
Step-by-step explanation:
total marks =15×4=60
Teena got =10×-2+4×5=20-20=0
her friend got=-4
correct answers=8
marks obtained=8×4=24
wrong answers=-28 marks= 28÷2=14
Answer:
total no. of questions=15
correct ans marks=4
incorrect ans marks= -2
a) since ten of her answers are incorrect she has gotten 5 answers as correct because total no. of questions is 15
so her marks for correct answers is 5* 4=20
she has 10 incorrect so marks for this is 10* -2= -20
( also its given that she has attempted all the questions)
total marks= marks for correct answers + marks for incorrect answers
= 20-20= 0
well, she has 0 marks in total
b) the friend has a total mark of -4
the no.of correct answers she got is 8
so marks for correct answers is 8*4=32
then let the number of incorrectly answered questions be 'X'
then marks for incorrect answers is -2*X
then total marks
-4 = 32 -2X
-2X= -4-32 = -36
so X=-36/-2= 18
now we got the answer as 18 i.e she attempted 18 questions but it was given in the beginning that there are only 15 questions in the exam
so i think there must be an error in the question
maybe the correction is that teena must have had 10 correct answers no incorrect then her marks is 30. i.e if she attempted all other questions and got it wrong.