PSAT Math Multiple-Choice Question 629: Answer and Explanation
Question: 629
A library fines a patron who fails to return a book on time the replacement cost of the book plus an additional 10 cents each day that the fine is not paid in full. On December 1, Jane borrowed a book with a replacement cost of $30. The book was due to be returned on December 14. Which function models the total amount of dollars (A ) that Jane will need to pay x days after December 14?
- A. A (x) = 30 + 10x
- B. A (x) = 30 + 0.1x
- C. A (x) = 30 + 1.4x
- D. A (x) = 30 - x
Correct Answer: B
Explanation:
(B) The book will have a fixed replacement cost of $30, so +30 will be a constant term in the function. For each day that the book goes unreturned past December 14, Jane owes another 10 cents. Thus on day 1 after the return date, she owes a $30 replacement fee and 10 more cents, for a total of $30.10. On the second day, she owes the $30 replacement fee and 2 days' worth of late fees, (2)(10) = 20 cents, for a total of $30.20. By continuing in this manner, on day x, Jane will owe the $30 replacement fee and x days' worth of late fees, which is (x)(10) = 10x cents or 0.1x dollars. The total cost is shown by A(x) = 30 + 0.1x.
This relationship is best described in choice (B).
Choice (A) is tempting, but you must remember that 10 cents is expressed in dollars as $0.10. Choice (A) instead indicates that Jane pays an additional $10 of fees every day plus the $30 replacement fee.
Test Information
- Use your browser's back button to return to your test results.
- Do more Math Multiple-Choice Tests tests.
More Tests
- PSAT Math Multiple-Choice Test 1
- PSAT Math Multiple-Choice Test 2
- PSAT Math Multiple-Choice Test 3
- PSAT Math Multiple-Choice Test 4
- PSAT Math Multiple-Choice Test 5
- PSAT Math Multiple-Choice Test 6
- PSAT Math Multiple-Choice Test 7
- PSAT Math Multiple-Choice Test 8
- PSAT Math Multiple-Choice Test 9
- PSAT Math Multiple-Choice Test 10
- PSAT Math Multiple-Choice Test 11
- PSAT Math Multiple-Choice Test 12
- PSAT Math Multiple-Choice Test 13
- PSAT Math Multiple-Choice Test 14
- PSAT Math Multiple-Choice Test 15
- PSAT Math Multiple-Choice Test 16
- PSAT Math Multiple-Choice Test 17
- PSAT Math Multiple-Choice Test 18
- PSAT Math Multiple-Choice Test 19
- PSAT Math Multiple-Choice Test 20
- PSAT Math Multiple-Choice Test 21
- PSAT Math Multiple-Choice Test 22
- PSAT Math Multiple-Choice Test 23
- PSAT Math Multiple-Choice Test 24
- PSAT Math Multiple-Choice Test 25