Question

The population of a town is 9000. If the male population increase by 7% and the female
population increses by 10%, the new population will be 9720. Find the number of
females.​

Answer 1

Answer:

I don't know ......___ hhjio

Answer 2

Answer:

The number of females is 3000.

Step-by-step explanation:

Let the number of males be x and the number of females be y.

The original population of the town can be expressed by the equation:

$x+y=9000...(i)$

The number of males was increased by 7%.

The new number of males is: $x+\frac{7}{100}x=1.07x$

The number of females was increased by 10%.

The new number of females is: $y+\frac{10}{100}y=1.1y$

The new population can be expressed by the equation:

$1.07x+1.1y=9720...(ii)$

Solve equations (i) and (ii) simultaneously.

Multiply (i) by 1.1 and subtract:

$1.1x+1.1y=9900\\-1.07x-1.1y=-9720\\\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\\0.03x=180\\x=6000$

Substitute the value of x in (i) to compute the value of y as follows:

$x+y=9000\\6000+y=9000\\y=3000$

Thus, the number of females is 3000.