The average cost of 8 books is $40.
After 4 books are removed,
the average cost of the remaining books is $20.
- What is the total cost of the 4 books that are removed?
- What is the average cost of the 4 books that are removed?
(a)
Total cost of 8 books
= 8 x 40
= $320
Number of remaining books
= 8 - 4
= 4
Total cost of the remaining books
= 4 x 20
= $80
Total cost of the 4 books that are removed
= 320 - 80
= $240
(b)
Average cost of the 4 books that are removed
= 240 ÷ 4
= $60
Answer(s): (a) $240; (b) $60