Five years ago, the number of trees in a forest was f. Today, the number of trees in the forest can be represented by the given expression.

1.33f

Which set of statements is true?
A.
The number of trees in the forest increased by 133%.
An equivalent expression that represents this situation is f + 1.33f.
B.
The number of trees in the forest decreased by 133%.
An equivalent expression that represents this situation is f − 1.33f.
C.
The number of trees in the forest decreased by 33%.
An equivalent expression that represents this situation is f − 0.33f.
D.
The number of trees in the forest increased by 33%.
An equivalent expression that represents this situation is f + 0.33f.

1 answer

To analyze the situation, we begin with the number of trees in the forest five years ago, which was \( f \). Today, the number of trees is represented by \( 1.33f \).

  1. Increase calculation:

    • The increase in the number of trees is: \[ 1.33f - f = 0.33f \]
    • To determine the percentage increase: \[ \text{Percentage Increase} = \left(\frac{0.33f}{f}\right) \times 100% = 33% \]
  2. Equivalent expression:

    • The total number of trees today can be expressed as: \[ f + 0.33f = 1.33f \]

Now we can evaluate the options provided in the statements:

A. The number of trees in the forest increased by 133%. An equivalent expression that represents this situation is \( f + 1.33f \).

  • False: The increase is 33%, not 133%. The expression is incorrect too; \( f + 1.33f = 2.33f \).

B. The number of trees in the forest decreased by 133%. An equivalent expression that represents this situation is \( f - 1.33f \).

  • False: There was an increase, not a decrease.

C. The number of trees in the forest decreased by 33%. An equivalent expression that represents this situation is \( f - 0.33f \).

  • False: There was an increase, not a decrease.

D. The number of trees in the forest increased by 33%. An equivalent expression that represents this situation is \( f + 0.33f \).

  • True: This accurately reflects the situation.

Thus, the correct answer is D.