The average cost of 6 books is $80.
After 2 new books are added,
the average cost of all the books is $70.
- What is the total cost of the 2 books that are added?
- What is the average cost of the 2 books that are added?
(a)
Total cost of 6 books
= 6 x 80
= $480
Number of books
= 6 + 2
= 8
Total cost of all the books
= 8 x 70
= $560
Total cost of the 2 books that are added
= 560 - 480
= $80
(b)
Average cost of the 2 books that are added
= 80 ÷ 2
= $40
Answer(s): (a) $80; (b) $40