SOLUTION: The average age of a group of 50 people is 45 years. Three members, ages 50, 60, and 72, leave the group. What is the average of the remaining 47 people?
You are given = = 45,
Hence, the sum of ages of 50 people is S = 45*50 = 2250.
When 3 members left the group, the sum S became 2250 - (50+60+72) = 2068.
Their average age is = 44 years.
Answer. 44 years.