πŸ“’ Too many exams? Don’t know which one suits you best? Book Your Free Expert πŸ‘‰ call Now!


    Question

    Some students (only boys and girls) from different

    schools appeared for an Olympiad exam. 20% of the boys and 15% of the girls failed the exam. The number of boys who passed the exam was 70 more than that of the girls who passed the exam'. A total of 90 students failed. Find the number of students that appeared for the exam.
    A 350 Correct Answer Incorrect Answer
    B 420 Correct Answer Incorrect Answer
    C 400 Correct Answer Incorrect Answer
    D 500 Correct Answer Incorrect Answer

    Solution

    Let the Number of boys and Girls who appeared in exam be x and y respectively, So, according to question- Number of boys passed in exam = [(100 - 20) × x]/100 = 0.80x Number of girls passed in exam = [(100 - 15) × y]/100 = 0.85y Condition (1) - ⇒ 0.80x = 0.85y + 70 ⇒ 0.80x - 0.85y = 70 ...(i) Condition (2) - Total failed students = 90 ⇒ 0.20x + 0.15y = 90 ...(ii) From eqn (1) - [4 × eqn (ii)] ⇒ (-0.85y) - 0.60y = 70 - 360 ⇒ 1.45y = 290 ⇒ y = 200 Put this value in eqn (i) ⇒ 0.80x = 0.85 × 200 + 70 ⇒ 0.80x = 170 + 70 = 240 ⇒ x = 300 So, total number of students appeared in exam = 300 + 200 = 500.

    Practice Next

    Relevant for Exams:

    ask-question