The average cost of 3 textbooks is $40.
After a textbook that costs $80 is removed,
- What is new total cost of all the remaining textbooks?
- What is new average cost of all the remaining textbooks?
(a)
Total cost of 3 textbooks
= 3 x 40
= $120
New total cost of all the remaining textbooks
= 120 - 80
= $40
(b)
Number of remaining textbooks
= 3 - 1
= 2
New average cost of all the remaining textbooks
= 40 ÷ 2
= $20
Answer(s): (a) $40; (b) $20