If 10 employees in an organization having an average weight of 73 kg leave and 5 employees having an average weight of 70 kg join, the average weight of the employees in the organization decreases by 0.4 kg. The average weight of all employees in the organization initially is 70 kg. If the number of employees initially in the organization is n, which of the following is/are correct? I. 73 employees are left II. n is a multiple of 16 III. 70 < n < 80
If 10 employees in an organization having an average weight of 73 kg leave and 5 employees having an average weight of 70 kg join, the average weight of the employees in the organization decreases by 0.4 kg. The average weight of all employees in the organization initially is 70 kg. If the number of employees initially in the organization is n, which of the following is/are correct? I. 73 employees are left II. n is a multiple of 16 III. 70 < n < 80 Correct Answer <p>Only II</p>
Given:
Average weight of n employees = 70 kg
Average weight of 10 employees who leave = 73 kg
Average weight of 5 employees who join = 70 kg
Difference in average weight = 0.4 kg
Formula Used:
Average = Sum of values/Number of values
Calculation:
Sum of the weight of 10 employees who leave/10 = 73 kg
⇒ Sum of the weight of 10 employees who leave = 730 kg
Sum of the weight of 5 employees who join/5 = 70 kg
⇒ Sum of the weight of 5 employees who join = 350 kg
Sum of the weight of n employees/n = 70 kg
⇒ Sum of the weight of n employees = 70n kg
∵ 10 employees leave and 5 join
∴ Number of employees left = n – 5
Sum of the weight of n – 5 employees/(n – 5) = 70 – 0.4
⇒ Sum of the weight of n – 5 employees = 69.6(n – 5)
⇒ 70n – 730 + 350 = 69.6n – 348
⇒ 0.4n = 32
⇒ n = 80 kg
I. 73 employees are left
80 – 10 + 5 = 75
⇒ I is not correct
II. n is a multiple of 16
80 = 5 × 16
⇒ II is correct
III. 70 < n < 80
⇒ 70 < n = 80
⇒ III is not correct
∴ Only II is correct