Digital PSAT Math Practice Question 213: Answer and Explanation

Question: 213

A botanist plants a small ivy plant and evaluates its growth function. She finds that at 2 months after planting, the plant is 5 inches tall; at 4 months after planting, the plant is 8 inches tall. Additionally, she has noticed that the plant has grown at a constant rate since its initial planting. Given this information, what was the plant's height in inches at the time it was planted?

Correct Answer: 2

Explanation:

(2) The plant increases 3 inches in height every 2 months. Simply backtrack 2 months from the time when it is 5 inches tall in order to see how tall it was when it was planted. 5 - 3 = 2 inches.