The average cost of 7 textbooks is $50.
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 7 textbooks
= 7 x 50
= $350
New total cost of all the textbooks
= 350 + 90
= $440
(b)
New total number of textbooks
= 7 + 1
= 8
New average cost of all the textbooks
= 440 ÷ 8
= $55
Answer(s): (a) $440; (b) $55