Question
In a school, the number of girls is 25% less than the
number of boys. If the number of boys increases by 20% and the number of girls decreases by 10%, find the overall percentage change in total students.Solution
ATQ, Let the initial number of boys be 100x
So, the initial number of girls = 100x × 0.75 = 75x
Total number of students = 100x + 75x = 175x Number of boys after increase = 100x × 1.20 = 120x
Number of girls after decrease = 75x × 0.90 = 67.5x New total number of students = 120x + 67.5x = 187.5x Overall change = 187.5x - 175x = 12.5x
Percentage change = (12.5x ÷ 175x) × 100 = 7.14% increase
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