Total sum = 8 * 14 = 112. Sum of 6 readings = 6 * 16 = 96. Sum of remaining two = 112 - 96 = 16. Average of remaining two = 16 / 2 = 8.
7502
A family consists of grandparents, parents, and 3 grandchildren. The average age of the grandparents is 67 years, parents is 35 years, and grandchildren is 6 years. Find the average age of the family.
Total members = 2 + 2 + 3 = 7. Total age = (2 * 67) + (2 * 35) + (3 * 6) = 134 + 70 + 18 = 222. Average = 222 / 7 = 31 5/7 years.
7503
The average age of 24 boys and their teacher is 15 years. If the teacher's age is excluded, their average age decreases by 1. What is the teacher's age?
Total age of 25 people = 25 * 15 = 375. After excluding the teacher, average is 14. Total age of 24 boys = 24 * 14 = 336. Teacher's age = 375 - 336 = 39 years.
7504
The average of four numbers is 20. If one number is 14, what is the average of the other three numbers?
