The average cost of 9 story books is $30.
After a story book that costs $70 is removed,
- What is new total cost of all the remaining story books?
- What is new average cost of all the remaining story books?
(a)
Total cost of 9 story books
= 9 x 30
= $270
New total cost of all the remaining story books
= 270 - 70
= $200
(b)
Number of remaining story books
= 9 - 1
= 8
New average cost of all the remaining story books
= 200 ÷ 8
= $25
Answer(s): (a) $200; (b) $25