Question

In a city number of male ,female ,children increases by 22%,17.5% and 13% respectively during 2021.find the population at the end of year 2021 of city if total population increases by 20% during this year and difference of male and hildren population in city was 40000 initially ?​

Answer 1

Given :-

• Male Population of city increases by = 22% .
• Female Population of city increases by = 17.5% .
• Children Population of city increases by = 13% .
• Total Population of city increases by = 20% .
• Difference between male and children population in city initially was = 40000.

Solution :-

Let us Assume that, initially Total number of children in the city were X and, Total No. of Female were Y . ( Also Assume Male > Children).

Than,

• Children = X
• Male = (X + 40000)
• Female = Y

Now,

→ Male inc. by 22% .

→ New Male Population = 122% of (x + 40000) = (122/100) * (x + 40000) = (61/50) * (x + 40000)

Similarly,

→ Female New Population = 117.5% of Y = (1175 * Y)/1000 = (47Y/40)

And,

→ Children New Population = 113% of X = (113X)/100

Also, Total Population This Year increased by 20% .

Therefore,

→ New Population = 120% of Total Population starting of 2021.

→ New male Population + Female New Population + Children New Population = 120% of [ Children + Male + Female ]

→ {61(x + 40000)/50} + (47Y/40) + (113X)/100 = 6(X + X + 40000 + Y) / 5

→ {61*4(X+40000) + 47*5Y + 113*2X} / 200 = (12X + 240000 + 6Y) / 5

→ 244(X + 40000) + 235Y + 226X = 480X + 9600000 + 240Y

→ 224X + 226X + 235Y + 9760000 = 480X + 9600000 + 240Y

→ 470X + 235Y + 9760000 = 480X + 9600000 + 240Y

→ 480X - 470X + 240Y - 235Y = 9760000 - 960000

→ 10X + 5Y = 160000

→ 5(2X + Y) = 160000

→ 2X + Y = 32000

→ Y = (32000 - 2X)

Therefore,

→ The population at the end of year 2021 of city = 120% of [ Children + Male + Female ]

→ New Population = (6/5) [ X + X + 40000 + (32000 - 2X)]

→ New Population = (6/5) [ 40000 + 32000 ]

→ New Population = (6/5) * 72000

→ New Population = 86,400 (Ans.)

Hence, The population at the end of year 2021 of city was 86,400.

Answer 2

Answer:

86400

Step-by-step explanation:

Let There is no children then male in 2021 is 40000. Now we can use allegation.

22% 17.5%

20%

2.5 : 2=5:4

according to question- 5unit=40000

9unit=72000(total population)

20% increase in 2021 so at the end of the year the population will be- 72000×6/5=86400