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?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
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