Probability

What is an outcome?

• The result of an experiment
• The chance or likelihood of an event
• A fraction, decimal, or a percent
• An activity that gives various results

Probability can be written as ...

• a fraction
• a decimal
• a percent
• all of the above

A jar contains 2 pink, 6 red, and 4 blue marbles. If you pick one marble without looking, what is the probability that the marble you pick will be red or blue?

• 5/6
• 1/2
• 1/3
• 1/6

A farm has 5 brown cows and 10 white cows. A fence is open and two cows escape. What is the probability that it will be a brown cow, then a white cow?

• 1/9
• 2/9
• 5/21
• 10/21

You flip a nickel three times.
Find the probability that all flips will land on tails.

• 1/2
• 1/4
• 1/6
• 1/8

What is the probability that a student does not play on a sports team? 

• .5
• .45
• .55

What is the probability that a student does play a sport given they do not play an instrument? 

• .2
• .2222
• .10
• .5

A pet store has two tanks of tropical fish. The first tank contains 10 blue fish and 9 yellow fish and the second tank contains 10 blue fish and 3 yellow fish. If Keisha randomly purchases a fish from each tank, what is the probability that both fish will be blue?

• 5/8

• 100/247

• 20/247

• 1/100

Which event is an independent event?

• Picking 2 students to each be line leader and door holder from a group of 20 students
• Picking 2 marbles from a bag without replacing the first marble
• Picking 2 crayons from a box at the same time (simultaneously) 
• Picking an earring, replacing it, then picking a 2nd earring

A science teacher gave her class two tests. 25% of the class passed both tests and 42% of the class passed the first test. What percent of those who passed the first test also passed the second?

• 59.5%

• 10.5%

• 1.6%

• Not enough information