In a school, the average height of the students of the tenth standard is 100 cm. The average height of boys is 118 cm, whereas the average height of girls is 95 cm. What is the number of girls in the class if there are 20 boys?

Correct option is A

Let the total number of girls be x
Sum of height of 20 boys = 20 ×118 = 2360 cm
Sum of height of x girls = x× 95 = 95x cm
Sum of all the students height = 100 (x+ 20)
ATQ,
100x+ 2000= 95x+ 2360
5x= 360
x= 72

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