In a mathamatics paper there are 10 problems. Each correct answer carries 5 marks where's for each incorrect answer 2marks are deducted from the marks scored . Aman answered all the question but got only 29 marks . Find the number of correct answer given by aman?
Answers
The number of correct answers given by Aman is 7.
Given:
The total number of problems = 10.
Each correct answer is awarded 5 marks and 2 marks are deducted for each incorrect answer.
To Find:
The number of correct answers given by Aman.
Solution:
Let the no. of right answers be 'x'.
Since Aman answered all the questions, the number of wrong answers
= (10-x).
We are given that each correct answer is awarded 5 marks.
⇒ The marks scored by Aman for correct answers = 5x.
Also, 2 marks are deducted for each incorrect answer.
⇒ The marks deducted for incorrect answers = 2(10-x).
Now,
Total marks obtained by Aman = Total marks for awarded correct answers - marks deducted for incorrect answers.
⇒ Total marks obtained by Aman = 5x - 2(10-x).
We are given that Aman answered all the questions and got 29 marks.
⇒ 5x - 2(10-x) = 29
⇒ 5x-20+2x = 29
⇒ 7x = 49
⇒ x = 7, i.e. Aman has answered 7 questions correctly.
Hence, the number of correct answers given by Aman is 7.
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