Coruja wrote:
The average (arithmetic mean) cost per book for the 12 books on a certain table is k dollars. If a book that costs 18 dollars is removed from the table and replaced by a book that costs 42 dollars, then in terms of k, what will be the average cost per book, in dollars, for the books in the table?
A) k+2
B) k - 2
C) 12+ 24/k
D) 12- 24/k
E) 12k-6
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he average (arithmetic mean) cost per book for the 12 books on a certain table is k dollars.
Total cost of 12 books = 12k
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If a book that costs 18 dollars is removed from the table and replaced by a book that costs 42 dollars
Total cost of books now = 12k - 18 + 42 Or, 12k +24
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what will be the average cost per book, in dollars, for the books in the table
Average cost will be \(\frac{(12k + 24 )}{24}\) = k + 2
Hence answer will be (A) k + 2
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67% (01:33) correct 
