Question

There are 40 questions in the test booklet of Mathematics Olympiad. If Stephen attempts all the questions and scores 80 marks when 5 marks are awarded for each correct answer and 3 marks is deducted for each incorrect answer then find the number of correct answers attempted by Stephen.

Solve with equation in one variable​

Answer 1

➤ Answer :

• The number of correct answers attempted by Stephen = 25. ( option d )

➤ Given :

• Total number of questions = 40.
• Marks scored by Stephen = 80.
• For each correct answer he get 5 marks.
• For each incorrect answer he get -3 marks.

➤ To Find :

• Number of correct answer attempted by Stephen.

➤ Step By Step Explanation :

➠ Assumption

Let us consider the number of correct answers attempted by Stephen be x and the number of incorrect answers be 40 - x.

➠ According to the question

Stephen get 5 marks for each correct answer and -3 for each incorrect answer.

So,

$\longmapsto\tt 5 \times x + (40 - x) \times ( - 3) = 80 \\ \\\longmapsto\tt 5x - 120 + 3x = 80 \\ \\\longmapsto\tt 8x - 120 = 80 \\ \\\longmapsto\tt 8x = 80 + 120 \\ \\\longmapsto\tt 8x = 200 \\ \\\longmapsto\tt x = \cancel\cfrac{200}{8} \\ \\\longmapsto\tt x = 25$

➵ Therefore, the number of correct answers attempted by Stephen = 25. ( option d )

_____________________

Answer 2

Answer:

Answer is 25

Step-by-step explanation:

Explaination is in the photo.