Question

The ratio of the no. of boys to the no. of girls in a school of 720 students is 3:5. If 18 new girls are admitted in the school, find how many new boys may be admitted so that the ratio of the no. of boys to the no. of girls may change to 2:3.

Answer 1

Step-by-step explanation:

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Answer 2

Ratio of no. girls to no. of boys = 3:5

➢ Let no. of girls = 3x

➢ Let no. of boys = 5x

➢ Let this ratio be = 3x:5x

Total no. of students = 270

↣ 3x + 5x = 270

↣ 8x = 270

↣ x = 270/9

↣ x = 90

∴ No. of girls = 3×90 = 270

∴ No. of boys = 5×90 = 450

➢ Now, 18 boys are added.

No. of boys = 468

Let the new ratio of no. girls to no. of boys=2x:3x

↣ 3x = 468

↣ x = 468/3

↣ x = 156

∴ New no. of girls = 156 × 2 = 312

∴ No. of girls to be added = 312-270 = 42

Your answer = 42