The average cost of 5 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 5 books
= 5 x 60
= $300
Number of remaining books
= 5 - 3
= 2
Total cost of the remaining books
= 2 x 30
= $60
Total cost of the 3 books that are removed
= 300 - 60
= $240
(b)
Average cost of the 3 books that are removed
= 240 ÷ 3
= $80
Answer(s): (a) $240; (b) $80