Question

In a Mathematics quiz, 20 problems were given. For each correct answer, 5 marks were awarded, and for each incorrect answer, 2 marks were deducted. Siti scored 51 marks. How many correct answers did she have?

a) 9
b) 10
c) 11
d) 12

Answer 1

After solving the equation derived from the given information, it is found that Siti had 13 correct answers, which does not match any of the provided options. There may be an error in the question or the answer choices.

Step-by-step explanation:

To solve this problem, let us define the number of correct answers Siti made as x. If x is the number of correct answers, then the number of incorrect answers would be 20 - x (because there are 20 questions in total). We know that for each correct answer, Siti gets 5 marks, and for each incorrect answer, 2 marks are deducted. Therefore, the total score can be represented by the equation:

5x - 2(20 - x) = 51

Let's solve this equation:

1. Multiply out the terms: 5x - 40 + 2x = 51
2. Combine like terms: 7x - 40 = 51
3. Add 40 to both sides: 7x = 91
4. Divide both sides by 7: x = 13

However, 13 is not one of the options provided. Let's recheck our calculation.

1. Multiply out the terms again: 5x - 40 + 2x = 51
2. Combine like terms again: 7x - 40 = 51
3. Add 40 to both sides again: 7x = 91
4. Divide both sides by 7 again: x = 91/7 = 13

It appears there is a mistake in the provided options. According to the calculations, Siti had 13 correct answers, which is not listed among the choices. The most likely possibility is that there was a mistake in the question or in the set of answer choices provided.