Free help with homework

Why join Brainly?

  • ask questions about your assignment
  • get answers with explanations
  • find similar questions

The average score of boys in an examination of a school is 71 and that of girls is 73. The average score if school in examination 71.8. Find the ratio if

number of boys to the number of girls that appeared in examination.



This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
Let the number of boys = x
number of girls = y
we need to find  \frac{x}{y} .

The average score of boys in the examination is 71
total score of boys = 71 
× x = 71x
The average score of girls in the examination is 73
total score of girls = 73 
× y = 73y
So total mark of school = 71x + 73y     ---------------(1)

average score if school in examination 71.8
so total mark = 71.8 
× (x+y)             -----------------(2)

From equations (1) and (2);
71x + 73y = 71.8(x+y)
⇒ 71x + 73y = 71.8x + 71.8y
⇒ 73y - 71.8y = 71.8x - 71x
⇒ 1.2y = 0.8x
⇒0.8x = 1.2y

 \frac{x}{y} = \frac{1.2}{0.8}= \frac{3}{2} =\boxed{3:2}

Ratio of boys and girls is 3:2.
0 0 0
The ratio of number of boys to that of girls appeared in the examination is 3:2.
0 0 0
The Brain
  • The Brain
  • Helper
Not sure about the answer?
Learn more with Brainly!
Having trouble with your homework?
Get free help!
  • 80% of questions are answered in under 10 minutes
  • Answers come with explanations, so that you can learn
  • Answer quality is ensured by our experts