The average cost of 4 textbooks is $40.
After another textbook that costs $90 is added,
- What is new total cost of all the textbooks?
- What is new average cost of all the textbooks?
(a)
Total cost of 4 textbooks
= 4 x 40
= $160
New total cost of all the textbooks
= 160 + 90
= $250
(b)
New total number of textbooks
= 4 + 1
= 5
New average cost of all the textbooks
= 250 ÷ 5
= $50
Answer(s): (a) $250; (b) $50