The male population of a city has increased by 20% from the previous year, while the female population has increased by 42.5%. If the total population of the city has increased by 30%, then the female population of the city was what percentage of male population in the previous year?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e 80%
Explanation :
Let the population of male and female of the city in previous year be x and y respectively.
Now, the increase in male population = 20%
Male population in present year = 120x/100 = 6x/5 ...(i)
the increase in female population = 42.5%
Female population in present year = 142.5y/100 = 57y/40 ...(ii)
The increase in total population (male + female) = 30%
Total population in present year = (x + y) × 13/10 ...(iii)
Now from equations (i), (ii) and (iii),
⇒ (x + y) × 13/10 = 6x/5 + 57y/40
⇒ 13x/10 - 6x/5 = 57y/40 - 13y/10
⇒ x/10 = 5y/40
⇒ x/y = 5/4
Now the required percentage = y/x × 100
⇒ 4/5 × 100 = 80.
Hence the percentage of female population is 80%.