The average cost of 6 textbooks is $30.
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 6 textbooks
= 6 x 30
= $180
New total cost of all the remaining textbooks
= 180 - 80
= $100
(b)
Number of remaining textbooks
= 6 - 1
= 5
New average cost of all the remaining textbooks
= 100 ÷ 5
= $20
Answer(s): (a) $100; (b) $20