Question

The ratio of the number of boys to girls of a school with $504$ students is $13:11$. What will be the new ratio if $12$ more girls are admitted?

• A. $91:81$
• B. $81:91$
• C. $9:10$
• D. $10:9$

Answer 1

Answer: (A)

$91:81$

$Numberofboys$ $=\frac{13}{(13+11)}\times 504=\frac{13}{24}\times 504$
$=13\times 21=273$

$\therefore Numberofgirls=504-273=231$

$\therefore Newratio=\frac{273}{(231+12)}=\frac{273}{243}=\frac{91}{81}$