The average cost of 9 colouring books is $40.
After a colouring book that costs $80 is removed,
- What is new total cost of all the remaining colouring books?
- What is new average cost of all the remaining colouring books?
(a)
Total cost of 9 colouring books
= 9 x 40
= $360
New total cost of all the remaining colouring books
= 360 - 80
= $280
(b)
Number of remaining colouring books
= 9 - 1
= 8
New average cost of all the remaining colouring books
= 280 ÷ 8
= $35
Answer(s): (a) $280; (b) $35