Question

A shape is picked at random from the group below. Which event has a theoretical probability of exactly 3/4? Check all that apply .

• not picking a square
• picking a square
• picking a triangle
• picking a shape that has only straight edges
• not picking a circle

Answer 1

Not picking a square.

Not picking a circle.

Explanation:

According to the image, there are 2 squares, 4 triangles and 2 circles. Let's find the probability of each figure:

`P_(square)=(2)/(8)=(1)/(4) \\P_(triangle)=(4)/(8)=(1)/(2) \\P_(circles)=(2)/(8)=(1)/(4)`

However, neither of this have a probability of 3/4.

That means the opposite events are probably the ones.

`P_(not \ square)=(6)/(8)=(3)/(4) \\P_(not \ triangle)=(4)/(8)=(1)/(2) \\P_(not \ circles)=(6)/(8)=(3)/(4)`

Therefore, not picking a square and not picking a circle have probability of 3/4 exactly.

Answer 2

Theoretical probability is a method to express that something will occur. It is calculated by dividing the number of favorable outcomes by the total number of outcomes.

So, the correct answers are :

A. not picking a square

D. picking a shape that has only straight edges

E. not picking a circle