New Enroll in RBI Grade B New Batch - Starts on May 21

    Question

    There are ‘x’ students in a class. Out of them

    ‘y’ are girls. The number of boys is 4 more than the number of girls. The sum of weight and the average weight of the girls is 754 kg and 58 kg, respectively. If 4 students are selected for a quiz competition then what will be the probability that the number of boys and the number of girls are equal?
    A 3536/9135 Correct Answer Incorrect Answer
    B 2244/1171 Correct Answer Incorrect Answer
    C 60/149 Correct Answer Incorrect Answer
    D 56/1615 Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    Total number of students = x The number of girls in the class = y The number of boys in the class = (y+4) Therefore the number of girls, => y = 754/58 = 13 Total number of girls = 13 Total number of boys = (13 + 4) = 17 Total number of students = (13 + 17) = 30 Required Probability = (13C2 × 17C2)/ 30C4 => (26 × 136)/27405 = 3536/9135

    Practice Next