A company contains two workplaces A and B. The sex ratios (female ∶ male) for the workplace A, workplace B and the total company are 2 ∶ 5, 16 ∶ 25 and 12 ∶ 25. By recruiting 9000 more people where number of females and males are in the ratio 2 ∶ 7, the sex ratio of the company changes to 19 ∶ 41. Then what is the total number of female employees working in workplace B?
A company contains two workplaces A and B. The sex ratios (female ∶ male) for the workplace A, workplace B and the total company are 2 ∶ 5, 16 ∶ 25 and 12 ∶ 25. By recruiting 9000 more people where number of females and males are in the ratio 2 ∶ 7, the sex ratio of the company changes to 19 ∶ 41. Then what is the total number of female employees working in workplace B? Correct Answer 16000
Let the number of female employees and male employees in workplace A be 2x and 5x respectively
Let the number of female employees and male employees in workplace B be 16y and 25y respectively
Total number of male employees = 5x + 25y
Total number of female employees = 2x + 16y
Total company’s sex ratio = 12/25
⇒ (2x + 16y)/(5x + 25y) = 12/25
⇒ (x + 8y)/(x + 5y) = 6/5
⇒ 5x + 40y = 6x + 30y
⇒ 10y = x
Now 9000 people are recruited with female and male ratio = 2 ∶ 7
∴ Number of male employees recruited = 7/9 × 9000 = 7000
Number of female employees recruited = 2000
New sex ratio = 19/41
⇒ (2x + 16y + 2000)/(5x + 25y + 7000) = 126/271
Substituting x = 10y
⇒ (36y + 2000)/(75y + 7000) = 19/41
Cross multiplying
⇒ 1476y + 82000 = 1425y + 133000
⇒ 51y = 51000
∴ y = 1000
Number of female employee in workplace B = 16y = 16000