Waec Model Questions Vol1 2021 Mathematics Question 1

A school organized a mathematics competition where students were required to solve various problems in different categories. The categories included Number and Numeration as well as Fractions, Decimals, and Percentages. Each category had a different scoring system. In the Number and Numeration category, each correct answer earned 5 points, while in the Fractions, Decimals, and Percentages category, each correct answer earned 3 points. If a student answered 12 questions correctly in the Number and Numeration category and 15 questions correctly in the Fractions, Decimals, and Percentages category, calculate the total score for the student. Additionally, if the student had answered 4 questions incorrectly in the Number and Numeration category, what would be the percentage of correct answers in that category? Finally, if the student aims to achieve a total score of at least 100 points in the competition, how many additional questions must they answer correctly in the Fractions, Decimals, and Percentages category?