ratio and proportion
Deepak BoraNewbie
The ratio of boys to the number of girls in a school of 560 pupils is 5 : 3 . if 10 new boys are admitted , find how many new girls may be admitted so that the ratio of the number of boys to the number of girls may change to 3 : 2
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Total number of students = 560
And Ratio of boys to the number of girls = 5:3
∴ Number of boys = 5/8 × 560
= 350
Number of girls = 3/8 × 560
= 210
After adding 10 new boys,total number of boys = 360
Let the number of girls added to make the new ratio (boys : girls)3:2 is ‘x’
∴ 360/210+x = 3:2
720 = 3(210+x)
720 = 630 + 3x
90 = 3x
∴ x= 30
So we have to add 30 girls to make ratio 3:2