Question

The ratio of male to female in a city is 3 ∶ 7. The children percentage among male and female is 25% and 30% respectively. If the number of adult males in the city is 18000, then find population of city.
1. 60,000
2. 40,000
3. 75,000
4. 80,000

Answer 1

Correct Answer - Option 4 : 80,000

Given:

Ratio of male to female = 3 ∶ 7

Children % among male = 25%

Children % among female = 30%

Number of adult males = 18000

Calculation:

Let the number of males and females be 3x and 7x respectively

Total population = 3x + 7x = 10x

Percentage of adult males = (100 - 25)% = 75%

Adult males = 75% of 3x = 9x/4

⇒ 18000 = 9x/4

⇒ 9x = 18000 × 4 = 72000

⇒ x = 8000

Total population = 10x = 10 × 8000 = 80000

∴ Total population of the city is 80,000