Final answer:
The probability of picking a green marble from a box containing 21 marbles is 10/21, which is approximately 47.6%.
Step-by-step explanation:
The probability of picking a green marble from a box containing 21 marbles, with 7 white, 4 black, and 10 green, requires calculating the ratio of green marbles to the total number of marbles.
The formula to determine probability is:
P(event) = Number of favorable outcomes / Total number of possible outcomes
In this scenario, the number of favorable outcomes for picking a green marble is 10 (since there are 10 green marbles), and the total number of possible outcomes is 21 (the total number of marbles in the box). Therefore, the probability of picking a green marble is:
P(green marble) = 10 / 21
To express this as a decimal, you can divide 10 by 21, which gives approximately 0.476. So, there is a 47.6% chance of picking a green marble from the box.