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The ration of the number of boys and girls who participated in an examination is $4:3.$ The total percentage of candidates who passed the examination is $80$ and the percentage of girls who passed the exam is $90.$ The percentage of boys who passed is _______.

- $55.50$
- $72.50$
- $80.50$
- $90.00$

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Y= 0.75 X (given)

Let, Y= total no. of girls and X= total no. of Boys

80% of the total students passed the exam successfully; (X+Y)*0.8

And 90% of the girls passed the exam too; 0.9*Y

thus we can write, (X+Y)*0.8 = 0.9*Y + X* (percentage of the boys who passed the exam)

1.75*0.8*X = X( 0.9*0.75 + Percentage of the boys who passed the exam)

Percentage of the boys who passed the exam = 72.5%

Let, Y= total no. of girls and X= total no. of Boys

80% of the total students passed the exam successfully; (X+Y)*0.8

And 90% of the girls passed the exam too; 0.9*Y

thus we can write, (X+Y)*0.8 = 0.9*Y + X* (percentage of the boys who passed the exam)

1.75*0.8*X = X( 0.9*0.75 + Percentage of the boys who passed the exam)

Percentage of the boys who passed the exam = 72.5%