Question

This table shows the number of seedlings for each plant type (A, B, C, D, and E).
Plant Types A B C D E
Number of Seedlings 100 140 80 60 40
A farmer conducted an inventory on his two square kilometers of rainforest; the results are in the table. He plans on randomly selecting a seedling to experiment on when he goes back to the forest. What is the probability that he will randomly pick a type B
plant? Write your answer in the simplest form of a fraction.

Answer 1

To find the probability of randomly selecting a type B plant seedling, we first need to determine the total number of seedlings and how many of those are type B.

From the table, the number of seedlings for each type is as follows:
- A: 100
- B: 140
- C: 80
- D: 60
- E: 40

First, calculate the total number of seedlings:

\[
\text{Total seedlings} = 100 + 140 + 80 + 60 + 40 = 420
\]

Next, identify the number of seedlings of type B, which is 140.

Now, the probability \( P \) of picking a type B plant is given by the formula:

\[
P(B) = \frac{\text{Number of type B seedlings}}{\text{Total number of seedlings}} = \frac{140}{420}
\]

Now, simplify the fraction:

1. The greatest common divisor (GCD) of 140 and 420 is 140.
2. Divide both the numerator and the denominator by their GCD:

\[
\frac{140 \div 140}{420 \div 140} = \frac{1}{3}
\]

Thus, the probability of randomly picking a type B plant is:

\[
\boxed{\frac{1}{3}}
\]