PSAT Math Multiple-Choice Question 817: Answer and Explanation

Question: 817

If the number of carp continues to grow at the same rate, what value comes closest to the likely number of carp in the sample in the year 2015?

• A. 52
• B. 83
• C. 129
• D. 172

Correct Answer: B

Explanation:

(B) In the 10-year period shown in the graph, the number of carp has increased by approximately 35. After 15 more years of growth, there will be approximately 1.5 times the amount of growth that occurred during the 10-year period. To find the approximate total number of carp in 2015, calculate 35 + (1.5 × 35) = 87.5. This value is closest to choice (B). Since the calculation is an approximation, having a little variance in the answer is acceptable.