in a group of 36 students boys and girls are in the ratio of 3:1 respectively how many more girls should be a should be included in the group so that the ratio becomes 9 : 5 respectively
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Answered by
9
Let the number of boys and girls be
x and y.
Given:
x:y = 3:1
x = 3k and y = k
As per given data,
x + y = 36
3k+k = 36
4k = 36
k = 9.
So there are 27 boys and 9 girls in the group.
Suppose m number of girls are added to group
Then their ratio becomes 9: 5
i. e 27/ (9+m) = 9/5
135= 81 + 9m
54 = 9m
m = 6
Therefore 6 girls should be added to group.
x and y.
Given:
x:y = 3:1
x = 3k and y = k
As per given data,
x + y = 36
3k+k = 36
4k = 36
k = 9.
So there are 27 boys and 9 girls in the group.
Suppose m number of girls are added to group
Then their ratio becomes 9: 5
i. e 27/ (9+m) = 9/5
135= 81 + 9m
54 = 9m
m = 6
Therefore 6 girls should be added to group.
Answered by
3
Let the number of the boys and the girls be 3x and x respectively.
∵ No. of girls + No. of Boys = 36
∴ x + 3x = 36
⇒ 4x = 36
⇒ x = 9
Number of the Girls = x = 9 girls..
Number of boys = 3x = 3 × 9
= 27 boys.
Let the numbers of the girls to be included in the groups be y.
∴ New numbers of the girls = 9 + y
According to the Question,
No. of boys/New number of girls = 9/5
∴ 27/(9 + y) = 9/5
⇒ 3/(9 + y) = 1/5
⇒ 15 = 9 + y
∴ y = 15 - 9
∴ y = 6
Hence, the number of the girls to be included so that the ratio of the number of boys and the girls will become 5:9 is 6.
Hope it helps.
∵ No. of girls + No. of Boys = 36
∴ x + 3x = 36
⇒ 4x = 36
⇒ x = 9
Number of the Girls = x = 9 girls..
Number of boys = 3x = 3 × 9
= 27 boys.
Let the numbers of the girls to be included in the groups be y.
∴ New numbers of the girls = 9 + y
According to the Question,
No. of boys/New number of girls = 9/5
∴ 27/(9 + y) = 9/5
⇒ 3/(9 + y) = 1/5
⇒ 15 = 9 + y
∴ y = 15 - 9
∴ y = 6
Hence, the number of the girls to be included so that the ratio of the number of boys and the girls will become 5:9 is 6.
Hope it helps.
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