in a test paper of Class 7 containing 30 questions 5 marks are awarded for every correct answer and -3 are awarded for every incorrect answer and zero for no answer naman scored 70 marks though he attempted 22 question then find how many questions had attempt incorrectly
Anonymous:
___k off
Answers
Answered by
9
Answer:
5 questions
Step-by-step explanation:
Let the questions scored correctly by Naman be x.
The questions scored wrongly will be = 22 - x
We rewrite this as follows :
5x + [-3 (22 - x)] = 5x - 66 + 3x
5x + 3x - 66 = 70
8x = 70 + 66
8x = 136
x = 136/8
x = 17
The questions he got correct were 17 questions.
The questions he got wrong were :
22 - 17 = 5
He got 5 questions wrong.
The answer is therefore 5.
Similar questions