The average cost of 4 books is $90.
After 2 books are removed,
the average cost of the remaining books is $60.
- What is the total cost of the 2 books that are removed?
- What is the average cost of the 2 books that are removed?
(a)
Total cost of 4 books
= 4 x 90
= $360
Number of remaining books
= 4 - 2
= 2
Total cost of the remaining books
= 2 x 60
= $120
Total cost of the 2 books that are removed
= 360 - 120
= $240
(b)
Average cost of the 2 books that are removed
= 240 ÷ 2
= $120
Answer(s): (a) $240; (b) $120