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?
Answer: A
Let the number of boyes and girls in the collage be \(7x\) and \(8x\) respectively. Their increased number is \((120\)% of \(7x)\) and \((110\)% of \(8x)\).
\(\Rightarrow (\frac{120}{100} \times 7x)\) and \((\frac{110}{100} \times 8x)\)
\(\Rightarrow \frac{42x}{5} \) and \(\frac{44x}{5}\)
\(\therefore\) The required ratio \(= (\frac{42x}{5} : \frac{44x}{5}) = 21 :22.\)