The average cost of 4 books is $50.
After 2 new books are added,
the average cost of all the books is $40.
- 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 4 books
= 4 x 50
= $200
Number of books
= 4 + 2
= 6
Total cost of all the books
= 6 x 40
= $240
Total cost of the 2 books that are added
= 240 - 200
= $40
(b)
Average cost of the 2 books that are added
= 40 ÷ 2
= $20
Answer(s): (a) $40; (b) $20