The average cost of 7 guide books is $40.
After a guide book that costs $70 is removed,
- What is new total cost of all the remaining guide books?
- What is new average cost of all the remaining guide books?
(a)
Total cost of 7 guide books
= 7 x 40
= $280
New total cost of all the remaining guide books
= 280 - 70
= $210
(b)
Number of remaining guide books
= 7 - 1
= 6
New average cost of all the remaining guide books
= 210 ÷ 6
= $35
Answer(s): (a) $210; (b) $35