The average cost of 6 books is $70.
After 3 books are removed,
the average cost of the remaining books is $60.
- 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 6 books
= 6 x 70
= $420
Number of remaining books
= 6 - 3
= 3
Total cost of the remaining books
= 3 x 60
= $180
Total cost of the 3 books that are removed
= 420 - 180
= $240
(b)
Average cost of the 3 books that are removed
= 240 ÷ 3
= $80
Answer(s): (a) $240; (b) $80