The average cost of 5 textbooks is $50.
After a textbook that costs $70 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 5 textbooks
= 5 x 50
= $250
New total cost of all the remaining textbooks
= 250 - 70
= $180
(b)
Number of remaining textbooks
= 5 - 1
= 4
New average cost of all the remaining textbooks
= 180 ÷ 4
= $45
Answer(s): (a) $180; (b) $45