Question

Q5. The ratio of the number of boys and girls in a college is 7 : 8. If the percentage increase in the number of boys and girls be 20% and 10% respectively, what will be the new ratio?

A.8 : 9
B.17 : 18
C.21 : 22
D.Cannot be determined

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Answer 1

8:9

your answer...............

Answer 2

Answer:-

Given:

Ratio of number of boys and girls in a college = 7 : 8.

Let the number of boys be 7x & number of girls be 8x.

Also given that,

Percentage increase in boys = 20%.

⟹ Number of boys = 7x * (100 + 20)/100

⟹ Number of boys = 7x * 120/100

⟹ Number of boys = 42x/5

Similarly,

Percentage increase in girls = 10%

⟹ Number of girls = 8x * (100 + 10)/100

⟹ Number of girls = 8x * 110/100

⟹ Number of girls = 44x/5

Hence,

New ratio = (42x/5) / (44x/5)

⟹ New ratio = 42x/5 * (5x/44)

⟹ New ratio = 21/22

⟹ New ratio = 21 : 22

∴ The new ratio of boys to girls will be 21 : 22 (Option - C).