The average cost of 6 books is $70.
After 4 books are removed,
the average cost of the remaining books is $50.
- 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 6 books
= 6 x 70
= $420
Number of remaining books
= 6 - 4
= 2
Total cost of the remaining books
= 2 x 50
= $100
Total cost of the 4 books that are removed
= 420 - 100
= $320
(b)
Average cost of the 4 books that are removed
= 320 ÷ 4
= $80
Answer(s): (a) $320; (b) $80