The price of an item that cost $43 in 2010 always increases by $3 per year. The current price in dollars, P, of the item can be represented by the equation P = 3t + 10, where t is the number of years since the item was first manufactured. Which of the following best explains the meaning of the number 10 in the equation?
A. It is the price of the item in 1999.
B. It is the price of the item in 2000.
C. It is the price of the item in 2001.
D. It is the annual increase in the price of the item.
Answer:A
The price of an item that cost $43 in 2010 always increases by $3 per year. The current price in dollars, P, of the item can be represented by the equation P = 3t + 10, where t is the number of years since the item was first manufactured. Which of the following best explains the meaning of the number 10 in the equation?
A. It is the price of the item in 1999. B. It is the price of the item in 2000. C. It is the price of the item in 2001. D. It is the annual increase in the price of the item.
Explanation: A Use Process of Elimination to solve this question. According to (A), the price of the item in 1999 was $10. According to the question, the price of the item in 2010 was $43, and the price of the item increased by $3 every year. 1999 is 11 years before 2010. Therefore, the price of the item in 1999 can be calculated as 43 - 11(3) = 10. Keep (A) but check the other answer choices just in case. Eliminate (B) and (C), since these answers could not also be correct. Eliminate (D) because the annual price increase is given as $3 in the question. Therefore, the correct answer is (A).