The average cost of 3 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 3 story books
= 3 x 30
= $90
New total cost of all the remaining story books
= 90 - 70
= $20
(b)
Number of remaining story books
= 3 - 1
= 2
New average cost of all the remaining story books
= 20 ÷ 2
= $10
Answer(s): (a) $20; (b) $10