The average cost of 8 books is $60.
After 3 books are removed,
the average cost of the remaining books is $30.
- What is the total cost of the 3 books that are removed?
- What is the average cost of the 3 books that are removed?
(a)
Total cost of 8 books
= 8 x 60
= $480
Number of remaining books
= 8 - 3
= 5
Total cost of the remaining books
= 5 x 30
= $150
Total cost of the 3 books that are removed
= 480 - 150
= $330
(b)
Average cost of the 3 books that are removed
= 330 ÷ 3
= $110
Answer(s): (a) $330; (b) $110