Question

Below given is the distribution of 2400 residents in terms of percentage.

	Adult Male	Adult Female	Child
$\%$ Living in Uptown	$9$	$8$	$6$
$\%$ Living in Midtown	$22$	$20$	$15$
$\%$ Living in Downtown	$21$	$22$	$12$
$\%$ Living in Suburbs	$48$	$50$	$67$

Centre Hill plans to annexe the area around a nearby lake. This new art of Centre Hill will be called, appropriately, The Annex. The Annex will add to the current population of Centre Hill. The perfect of adult males living in Uptown will decrease to $6\%$ after incorporating The Annex into Centre Hill. If the information from Part $1$ holds true for the original four districts of the city of centre Hill, then how many adults makes live in The Annex?

• A. $250$
• B. $350$
• C. $240$
• D. $340$

Answer 1

The correct option is A $250$

You can determine that the number of adult males prior to addition of annex $=1200-700=500$

The original percentage living uptownis $9\%$ of $500=\frac{9}{100}\times 500=45$

Since the question states that the percentage of adult males living uptown decreases to $6\%$, you can conclude that the 45 adult males living uptown after annexation constitute $6\%$ of the total male population:

$45=\frac{6}{100}x\Rightarrow x=750$

Since, original number of males $=500$

Additional adult males live in the Annex $=750-500=250$