The average cost of 4 textbooks is $30.
After a textbook that costs $60 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 4 textbooks
= 4 x 30
= $120
New total cost of all the remaining textbooks
= 120 - 60
= $60
(b)
Number of remaining textbooks
= 4 - 1
= 3
New average cost of all the remaining textbooks
= 60 ÷ 3
= $20
Answer(s): (a) $60; (b) $20