Answer:
5/6
Explanation:
Step 1: Determine the total number of four-sided shapes:
We know that pentagons are five-sided, triangles are three sides and trapezoids are four-sided. However, pentagons have at least five sides and therefore we include them since they have at least four sides. Thus, there are 15 four-sided shapes present among all the shapes Tracy has as 7 + 8 = 15.
Step 2: Determine the total number of shapes present:
Now we must add up the total number of shapes Tracy has:
7 + 3 + 8
10 + 8
18
Thus, Tracy has a total of 18 shapes.
Step 3: Divide the total number of four-sided shapes by the total number of shapes to determine probability of picking a four-sided shapes:
15/18
5/6
Thus, the probability that Tracy picks a shape with at least four sides is 5/6.
If this answer is wrong, it is possible that your teacher wants to know the probability of picking a shape with only four sides. Then you'd write 4/9 as you'd only include the trapezoids since only they have just four sides while the pentagons also have four sides but also an additional side: