The average cost of 6 books is $80.
After 4 books are removed,
the average cost of the remaining books is $60.
- 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 80
= $480
Number of remaining books
= 6 - 4
= 2
Total cost of the remaining books
= 2 x 60
= $120
Total cost of the 4 books that are removed
= 480 - 120
= $360
(b)
Average cost of the 4 books that are removed
= 360 ÷ 4
= $90
Answer(s): (a) $360; (b) $90