Average age of group A of 20 students is 40 years. Average age of group B of 40 students is 'x' years. Combined average age of group A and group B is 50 years. What is the value of 'x'?
Show answer & explanation
Correct answer: A
Explanation
Given:
Students in Group A = 20
Average Age = 40 years
Students in Group B = 40
Average Age = x years
Combined Average Age = 50 years
According to the formula:
Average = Total Age / Total Number of Individuals
Total Age of Group A = 20 × 40 = 800
Total Age of Group B = 40x
Total Students = 20 + 40 = 60
Combined Average:
(800 + 40x) / 60 = 50
800 + 40x = 3000
40x = 2200
x = 55 years