The ratio of the number of boys and girls in a school is 9 7. If the number of boys increases by 40%, and that of girls by 20% what will be the new ratio of the boys and girls respectively ?
Let number of boys='9x'.
then, number of girls= '7x'.
After 40% increase, new number of boys=$$9x(1+\frac{40}{100})$$.
=$$9x\times1.4$$.
=$$12.6x$$.
After 20% increase, new number of girls=$$7x(1+\frac{20}{100})$$.
=$$7x\times1.2$$.
=$$8.4x$$.
Hence, new ratio of boys to girls=$$\frac{12.6}{8.4}$$.
=$$\frac{3}{2}$$.
Therefore, Option A is correct.
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