Explanation:

Correct option:3

Solution:

The average weight of all the 200 employees in an office is 68.2 kg, where 2/5 of the employees are ladies and the ratio of the average weight of a man to that of a woman is 7 : 5. 
Total = Average x Number of entities

Number of female employees = 200 x 2/5 = 80
Number of male employees = 200 - 80 = 120
Total weight of 200 employees = 200 x 68.2 = 13640 kg
Let the average weight of a male and female employee be 7k and 5k respectively.
According to the question, (80 x 5k) + (120 x 7k) = 13640
400k + 840k = 13640
 k = 13640/1240
k = 11
5k = 55
:. The average weight of a female employee is 55 kg.