Multiple choice

In a certain year the percentage of males, females in a village are 45% and 35% respectively and the remaining are children. In the next year the number of males is increased by 100/9%, number of females is increased by 500 and the number of children is increased by 25% due to this change the population of village is increased by 1200. Find the number of females initially present in the village.

  1. 2350

  2. 2230

  3. 2450

  4. 2000

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let the initial population be P. Then males = 45% of P = 0.45P, females = 35% of P = 0.35P, and children = 20% of P = 0.20P. Male increase = 100/9% of 0.45P = (100/9 × 1/100) × 0.45P = 0.05P. Female increase = 500. Child increase = 25% of 0.20P = 0.05P. Total increase = 0.05P + 500 + 0.05P = 0.10P + 500 = 1200. Solving: 0.10P = 700, so P = 7000. Initial females = 0.35 × 7000 = 2450.